CDSPass.cpp

   1 //===-- CDSPass.cpp - xxx -------------------------------===//
   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 // This file is distributed under the University of Illinois Open Source
   7 // License. See LICENSE.TXT for details.
   8 //
   9 //===----------------------------------------------------------------------===//
  10 //
  11 // This file is a modified version of ThreadSanitizer.cpp, a part of a race detector.
  12 //
  13 // The tool is under development, for the details about previous versions see
  14 // http://code.google.com/p/data-race-test
  15 //
  16 // The instrumentation phase is quite simple:
  17 //   - Insert calls to run-time library before every memory access.
  18 //      - Optimizations may apply to avoid instrumenting some of the accesses.
  19 //   - Insert calls at function entry/exit.
  20 // The rest is handled by the run-time library.
  21 //===----------------------------------------------------------------------===//
  22
  23 #include "llvm/ADT/Statistic.h"
  24 #include "llvm/ADT/StringExtras.h"
  25 #include "llvm/ADT/SmallString.h"
  26 #include "llvm/Analysis/ValueTracking.h"
  27 #include "llvm/Analysis/CaptureTracking.h"
  28 #include "llvm/Analysis/LoopInfo.h"
  29 #include "llvm/IR/BasicBlock.h"
  30 #include "llvm/IR/Function.h"
  31 #include "llvm/IR/IRBuilder.h"
  32 #include "llvm/IR/Instructions.h"
  33 #include "llvm/IR/IntrinsicInst.h"
  34 #include "llvm/IR/LLVMContext.h"
  35 #include "llvm/IR/LegacyPassManager.h"
  36 #include "llvm/IR/Module.h"
  37 #include "llvm/IR/PassManager.h"
  38 #include "llvm/Pass.h"
  39 #include "llvm/ProfileData/InstrProf.h"
  40 #include "llvm/Support/raw_ostream.h"
  41 #include "llvm/Support/AtomicOrdering.h"
  42 #include "llvm/Support/Debug.h"
  43 #include "llvm/Transforms/Scalar.h"
  44 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
  45 #include "llvm/Transforms/Utils/EscapeEnumerator.h"
  46 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
  47 #include <vector>
  48
  49 using namespace llvm;
  50
  51 #define CDS_DEBUG
  52 #define DEBUG_TYPE "CDS"
  53 #include <llvm/IR/DebugLoc.h>
  54
  55 static inline Value *getPosition( Instruction * I, IRBuilder <> IRB, bool print = false)
  56 {
  57         const DebugLoc & debug_location = I->getDebugLoc ();
  58         std::string position_string;
  59         {
  60                 llvm::raw_string_ostream position_stream (position_string);
  61                 debug_location . print (position_stream);
  62         }
  63
  64         if (print) {
  65                 errs() << position_string << "\n";
  66         }
  67
  68         return IRB.CreateGlobalStringPtr (position_string);
  69 }
  70
  71 static inline bool checkSignature(Function * func, Value * args[]) {
  72         FunctionType * FType = func->getFunctionType();
  73         for (unsigned i = 0 ; i < FType->getNumParams(); i++) {
  74                 if (FType->getParamType(i) != args[i]->getType()) {
  75 #ifdef CDS_DEBUG
  76                         errs() << "expects: " << *FType->getParamType(i)
  77                                         << "\tbut receives: " << *args[i]->getType() << "\n";
  78 #endif
  79                         return false;
  80                 }
  81         }
  82
  83         return true;
  84 }
  85
  86 STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
  87 STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
  88 STATISTIC(NumOmittedReadsBeforeWrite,
  89           "Number of reads ignored due to following writes");
  90 STATISTIC(NumAccessesWithBadSize, "Number of accesses with bad size");
  91 // STATISTIC(NumInstrumentedVtableWrites, "Number of vtable ptr writes");
  92 // STATISTIC(NumInstrumentedVtableReads, "Number of vtable ptr reads");
  93 STATISTIC(NumOmittedReadsFromConstantGlobals,
  94           "Number of reads from constant globals");
  95 STATISTIC(NumOmittedReadsFromVtable, "Number of vtable reads");
  96 STATISTIC(NumOmittedNonCaptured, "Number of accesses ignored due to capturing");
  97
  98 // static const char *const kCDSModuleCtorName = "cds.module_ctor";
  99 // static const char *const kCDSInitName = "cds_init";
 100
 101 Type * OrdTy;
 102 Type * IntPtrTy;
 103 Type * Int8PtrTy;
 104 Type * Int16PtrTy;
 105 Type * Int32PtrTy;
 106 Type * Int64PtrTy;
 107
 108 Type * VoidTy;
 109
 110 static const size_t kNumberOfAccessSizes = 4;
 111
 112 int getAtomicOrderIndex(AtomicOrdering order) {
 113         switch (order) {
 114                 case AtomicOrdering::Monotonic:
 115                         return (int)AtomicOrderingCABI::relaxed;
 116                 //case AtomicOrdering::Consume:         // not specified yet
 117                 //      return AtomicOrderingCABI::consume;
 118                 case AtomicOrdering::Acquire:
 119                         return (int)AtomicOrderingCABI::acquire;
 120                 case AtomicOrdering::Release:
 121                         return (int)AtomicOrderingCABI::release;
 122                 case AtomicOrdering::AcquireRelease:
 123                         return (int)AtomicOrderingCABI::acq_rel;
 124                 case AtomicOrdering::SequentiallyConsistent:
 125                         return (int)AtomicOrderingCABI::seq_cst;
 126                 default:
 127                         // unordered or Not Atomic
 128                         return -1;
 129         }
 130 }
 131
 132 AtomicOrderingCABI indexToAtomicOrder(int index) {
 133         switch (index) {
 134                 case 0:
 135                         return AtomicOrderingCABI::relaxed;
 136                 case 1:
 137                         return AtomicOrderingCABI::consume;
 138                 case 2:
 139                         return AtomicOrderingCABI::acquire;
 140                 case 3:
 141                         return AtomicOrderingCABI::release;
 142                 case 4:
 143                         return AtomicOrderingCABI::acq_rel;
 144                 case 5:
 145                         return AtomicOrderingCABI::seq_cst;
 146                 default:
 147                         errs() << "Bad Atomic index\n";
 148                         return AtomicOrderingCABI::seq_cst;
 149         }
 150 }
 151
 152 /* According to atomic_base.h: __cmpexch_failure_order */
 153 int AtomicCasFailureOrderIndex(int index) {
 154         AtomicOrderingCABI succ_order = indexToAtomicOrder(index);
 155         AtomicOrderingCABI fail_order;
 156         if (succ_order == AtomicOrderingCABI::acq_rel)
 157                 fail_order = AtomicOrderingCABI::acquire;
 158         else if (succ_order == AtomicOrderingCABI::release)
 159                 fail_order = AtomicOrderingCABI::relaxed;
 160         else
 161                 fail_order = succ_order;
 162
 163         return (int) fail_order;
 164 }
 165
 166 /* The original function checkSanitizerInterfaceFunction was defined
 167  * in llvm/Transforms/Utils/ModuleUtils.h
 168  */
 169 static Function * checkCDSPassInterfaceFunction(Constant *FuncOrBitcast) {
 170         if (isa<Function>(FuncOrBitcast))
 171                 return cast<Function>(FuncOrBitcast);
 172         FuncOrBitcast->print(errs());
 173         errs() << "\n";
 174         std::string Err;
 175         raw_string_ostream Stream(Err);
 176         Stream << "CDSPass interface function redefined: " << *FuncOrBitcast;
 177         report_fatal_error(Err);
 178 }
 179
 180 namespace {
 181         struct CDSPass : public FunctionPass {
 182                 CDSPass() : FunctionPass(ID) {}
 183                 StringRef getPassName() const override;
 184                 bool runOnFunction(Function &F) override;
 185                 bool doInitialization(Module &M) override;
 186                 static char ID;
 187
 188         private:
 189                 void initializeCallbacks(Module &M);
 190                 bool instrumentLoadOrStore(Instruction *I, const DataLayout &DL);
 191                 bool instrumentVolatile(Instruction *I, const DataLayout &DL);
 192                 bool instrumentMemIntrinsic(Instruction *I);
 193                 bool isAtomicCall(Instruction *I);
 194                 bool instrumentAtomic(Instruction *I, const DataLayout &DL);
 195                 bool instrumentAtomicCall(CallInst *CI, const DataLayout &DL);
 196                 bool shouldInstrumentBeforeAtomics(Instruction *I);
 197                 void chooseInstructionsToInstrument(SmallVectorImpl<Instruction *> &Local,
 198                                                                                         SmallVectorImpl<Instruction *> &All,
 199                                                                                         const DataLayout &DL);
 200                 bool addrPointsToConstantData(Value *Addr);
 201                 int getMemoryAccessFuncIndex(Value *Addr, const DataLayout &DL);
 202                 bool instrumentLoops(Function &F);
 203
 204                 Function * CDSFuncEntry;
 205                 Function * CDSFuncExit;
 206
 207                 Function * CDSLoad[kNumberOfAccessSizes];
 208                 Function * CDSStore[kNumberOfAccessSizes];
 209                 Function * CDSVolatileLoad[kNumberOfAccessSizes];
 210                 Function * CDSVolatileStore[kNumberOfAccessSizes];
 211                 Function * CDSAtomicInit[kNumberOfAccessSizes];
 212                 Function * CDSAtomicLoad[kNumberOfAccessSizes];
 213                 Function * CDSAtomicStore[kNumberOfAccessSizes];
 214                 Function * CDSAtomicRMW[AtomicRMWInst::LAST_BINOP + 1][kNumberOfAccessSizes];
 215                 Function * CDSAtomicCAS_V1[kNumberOfAccessSizes];
 216                 Function * CDSAtomicCAS_V2[kNumberOfAccessSizes];
 217                 Function * CDSAtomicThreadFence;
 218                 Function * MemmoveFn, * MemcpyFn, * MemsetFn;
 219                 // Function * CDSCtorFunction;
 220
 221                 std::vector<StringRef> AtomicFuncNames;
 222                 std::vector<StringRef> PartialAtomicFuncNames;
 223         };
 224 }
 225
 226 StringRef CDSPass::getPassName() const {
 227         return "CDSPass";
 228 }
 229
 230 void CDSPass::initializeCallbacks(Module &M) {
 231         LLVMContext &Ctx = M.getContext();
 232         AttributeList Attr;
 233         Attr = Attr.addAttribute(Ctx, AttributeList::FunctionIndex,
 234                         Attribute::NoUnwind);
 235
 236         Type * Int1Ty = Type::getInt1Ty(Ctx);
 237         Type * Int32Ty = Type::getInt32Ty(Ctx);
 238         OrdTy = Type::getInt32Ty(Ctx);
 239
 240         Int8PtrTy  = Type::getInt8PtrTy(Ctx);
 241         Int16PtrTy = Type::getInt16PtrTy(Ctx);
 242         Int32PtrTy = Type::getInt32PtrTy(Ctx);
 243         Int64PtrTy = Type::getInt64PtrTy(Ctx);
 244
 245         VoidTy = Type::getVoidTy(Ctx);
 246
 247         CDSFuncEntry = checkCDSPassInterfaceFunction(
 248                                                 M.getOrInsertFunction("cds_func_entry",
 249                                                 Attr, VoidTy, Int8PtrTy));
 250         CDSFuncExit = checkCDSPassInterfaceFunction(
 251                                                 M.getOrInsertFunction("cds_func_exit",
 252                                                 Attr, VoidTy, Int8PtrTy));
 253
 254         // Get the function to call from our untime library.
 255         for (unsigned i = 0; i < kNumberOfAccessSizes; i++) {
 256                 const unsigned ByteSize = 1U << i;
 257                 const unsigned BitSize = ByteSize * 8;
 258
 259                 std::string ByteSizeStr = utostr(ByteSize);
 260                 std::string BitSizeStr = utostr(BitSize);
 261
 262                 Type *Ty = Type::getIntNTy(Ctx, BitSize);
 263                 Type *PtrTy = Ty->getPointerTo();
 264
 265                 // uint8_t cds_atomic_load8 (void * obj, int atomic_index)
 266                 // void cds_atomic_store8 (void * obj, int atomic_index, uint8_t val)
 267                 SmallString<32> LoadName("cds_load" + BitSizeStr);
 268                 SmallString<32> StoreName("cds_store" + BitSizeStr);
 269                 SmallString<32> VolatileLoadName("cds_volatile_load" + BitSizeStr);
 270                 SmallString<32> VolatileStoreName("cds_volatile_store" + BitSizeStr);
 271                 SmallString<32> AtomicInitName("cds_atomic_init" + BitSizeStr);
 272                 SmallString<32> AtomicLoadName("cds_atomic_load" + BitSizeStr);
 273                 SmallString<32> AtomicStoreName("cds_atomic_store" + BitSizeStr);
 274
 275                 CDSLoad[i]  = checkCDSPassInterfaceFunction(
 276                                                         M.getOrInsertFunction(LoadName, Attr, VoidTy, Int8PtrTy));
 277                 CDSStore[i] = checkCDSPassInterfaceFunction(
 278                                                         M.getOrInsertFunction(StoreName, Attr, VoidTy, Int8PtrTy));
 279                 CDSVolatileLoad[i]  = checkCDSPassInterfaceFunction(
 280                                                                 M.getOrInsertFunction(VolatileLoadName,
 281                                                                 Attr, Ty, PtrTy, Int8PtrTy));
 282                 CDSVolatileStore[i] = checkCDSPassInterfaceFunction(
 283                                                                 M.getOrInsertFunction(VolatileStoreName,
 284                                                                 Attr, VoidTy, PtrTy, Ty, Int8PtrTy));
 285                 CDSAtomicInit[i] = checkCDSPassInterfaceFunction(
 286                                                         M.getOrInsertFunction(AtomicInitName,
 287                                                         Attr, VoidTy, PtrTy, Ty, Int8PtrTy));
 288                 CDSAtomicLoad[i]  = checkCDSPassInterfaceFunction(
 289                                                                 M.getOrInsertFunction(AtomicLoadName,
 290                                                                 Attr, Ty, PtrTy, OrdTy, Int8PtrTy));
 291                 CDSAtomicStore[i] = checkCDSPassInterfaceFunction(
 292                                                                 M.getOrInsertFunction(AtomicStoreName,
 293                                                                 Attr, VoidTy, PtrTy, Ty, OrdTy, Int8PtrTy));
 294
 295                 for (int op = AtomicRMWInst::FIRST_BINOP;
 296                         op <= AtomicRMWInst::LAST_BINOP; ++op) {
 297                         CDSAtomicRMW[op][i] = nullptr;
 298                         std::string NamePart;
 299
 300                         if (op == AtomicRMWInst::Xchg)
 301                                 NamePart = "_exchange";
 302                         else if (op == AtomicRMWInst::Add)
 303                                 NamePart = "_fetch_add";
 304                         else if (op == AtomicRMWInst::Sub)
 305                                 NamePart = "_fetch_sub";
 306                         else if (op == AtomicRMWInst::And)
 307                                 NamePart = "_fetch_and";
 308                         else if (op == AtomicRMWInst::Or)
 309                                 NamePart = "_fetch_or";
 310                         else if (op == AtomicRMWInst::Xor)
 311                                 NamePart = "_fetch_xor";
 312                         else
 313                                 continue;
 314
 315                         SmallString<32> AtomicRMWName("cds_atomic" + NamePart + BitSizeStr);
 316                         CDSAtomicRMW[op][i] = checkCDSPassInterfaceFunction(
 317                                                                         M.getOrInsertFunction(AtomicRMWName,
 318                                                                         Attr, Ty, PtrTy, Ty, OrdTy, Int8PtrTy));
 319                 }
 320
 321                 // only supportes strong version
 322                 SmallString<32> AtomicCASName_V1("cds_atomic_compare_exchange" + BitSizeStr + "_v1");
 323                 SmallString<32> AtomicCASName_V2("cds_atomic_compare_exchange" + BitSizeStr + "_v2");
 324                 CDSAtomicCAS_V1[i] = checkCDSPassInterfaceFunction(
 325                                                                 M.getOrInsertFunction(AtomicCASName_V1,
 326                                                                 Attr, Ty, PtrTy, Ty, Ty, OrdTy, OrdTy, Int8PtrTy));
 327                 CDSAtomicCAS_V2[i] = checkCDSPassInterfaceFunction(
 328                                                                 M.getOrInsertFunction(AtomicCASName_V2,
 329                                                                 Attr, Int1Ty, PtrTy, PtrTy, Ty, OrdTy, OrdTy, Int8PtrTy));
 330         }
 331
 332         CDSAtomicThreadFence = checkCDSPassInterfaceFunction(
 333                         M.getOrInsertFunction("cds_atomic_thread_fence", Attr, VoidTy, OrdTy, Int8PtrTy));
 334
 335         MemmoveFn = checkCDSPassInterfaceFunction(
 336                                         M.getOrInsertFunction("memmove", Attr, Int8PtrTy, Int8PtrTy,
 337                                         Int8PtrTy, IntPtrTy));
 338         MemcpyFn = checkCDSPassInterfaceFunction(
 339                                         M.getOrInsertFunction("memcpy", Attr, Int8PtrTy, Int8PtrTy,
 340                                         Int8PtrTy, IntPtrTy));
 341         MemsetFn = checkCDSPassInterfaceFunction(
 342                                         M.getOrInsertFunction("memset", Attr, Int8PtrTy, Int8PtrTy,
 343                                         Int32Ty, IntPtrTy));
 344 }
 345
 346 bool CDSPass::doInitialization(Module &M) {
 347         const DataLayout &DL = M.getDataLayout();
 348         IntPtrTy = DL.getIntPtrType(M.getContext());
 349
 350         // createSanitizerCtorAndInitFunctions is defined in "llvm/Transforms/Utils/ModuleUtils.h"
 351         // We do not support it yet
 352         /*
 353         std::tie(CDSCtorFunction, std::ignore) = createSanitizerCtorAndInitFunctions(
 354                         M, kCDSModuleCtorName, kCDSInitName, {}, {});
 355
 356         appendToGlobalCtors(M, CDSCtorFunction, 0);
 357         */
 358
 359         AtomicFuncNames =
 360         {
 361                 "atomic_init", "atomic_load", "atomic_store",
 362                 "atomic_fetch_", "atomic_exchange", "atomic_compare_exchange_"
 363         };
 364
 365         PartialAtomicFuncNames =
 366         {
 367                 "load", "store", "fetch", "exchange", "compare_exchange_"
 368         };
 369
 370         return true;
 371 }
 372
 373 static bool isVtableAccess(Instruction *I) {
 374         if (MDNode *Tag = I->getMetadata(LLVMContext::MD_tbaa))
 375                 return Tag->isTBAAVtableAccess();
 376         return false;
 377 }
 378
 379 // Do not instrument known races/"benign races" that come from compiler
 380 // instrumentatin. The user has no way of suppressing them.
 381 static bool shouldInstrumentReadWriteFromAddress(const Module *M, Value *Addr) {
 382         // Peel off GEPs and BitCasts.
 383         Addr = Addr->stripInBoundsOffsets();
 384
 385         if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Addr)) {
 386                 if (GV->hasSection()) {
 387                         StringRef SectionName = GV->getSection();
 388                         // Check if the global is in the PGO counters section.
 389                         auto OF = Triple(M->getTargetTriple()).getObjectFormat();
 390                         if (SectionName.endswith(
 391                               getInstrProfSectionName(IPSK_cnts, OF, /*AddSegmentInfo=*/false)))
 392                                 return false;
 393                 }
 394
 395                 // Check if the global is private gcov data.
 396                 if (GV->getName().startswith("__llvm_gcov") ||
 397                 GV->getName().startswith("__llvm_gcda"))
 398                 return false;
 399         }
 400
 401         // Do not instrument acesses from different address spaces; we cannot deal
 402         // with them.
 403         if (Addr) {
 404                 Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
 405                 if (PtrTy->getPointerAddressSpace() != 0)
 406                         return false;
 407         }
 408
 409         return true;
 410 }
 411
 412 bool CDSPass::addrPointsToConstantData(Value *Addr) {
 413         // If this is a GEP, just analyze its pointer operand.
 414         if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Addr))
 415                 Addr = GEP->getPointerOperand();
 416
 417         if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Addr)) {
 418                 if (GV->isConstant()) {
 419                         // Reads from constant globals can not race with any writes.
 420                         NumOmittedReadsFromConstantGlobals++;
 421                         return true;
 422                 }
 423         } else if (LoadInst *L = dyn_cast<LoadInst>(Addr)) {
 424                 if (isVtableAccess(L)) {
 425                         // Reads from a vtable pointer can not race with any writes.
 426                         NumOmittedReadsFromVtable++;
 427                         return true;
 428                 }
 429         }
 430         return false;
 431 }
 432
 433 bool CDSPass::shouldInstrumentBeforeAtomics(Instruction * Inst) {
 434         if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
 435                 AtomicOrdering ordering = LI->getOrdering();
 436                 if ( isAtLeastOrStrongerThan(ordering, AtomicOrdering::Acquire) )
 437                         return true;
 438         } else if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
 439                 AtomicOrdering ordering = SI->getOrdering();
 440                 if ( isAtLeastOrStrongerThan(ordering, AtomicOrdering::Acquire) )
 441                         return true;
 442         } else if (AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(Inst)) {
 443                 AtomicOrdering ordering = RMWI->getOrdering();
 444                 if ( isAtLeastOrStrongerThan(ordering, AtomicOrdering::Acquire) )
 445                         return true;
 446         } else if (AtomicCmpXchgInst *CASI = dyn_cast<AtomicCmpXchgInst>(Inst)) {
 447                 AtomicOrdering ordering = CASI->getSuccessOrdering();
 448                 if ( isAtLeastOrStrongerThan(ordering, AtomicOrdering::Acquire) )
 449                         return true;
 450         } else if (FenceInst *FI = dyn_cast<FenceInst>(Inst)) {
 451                 AtomicOrdering ordering = FI->getOrdering();
 452                 if ( isAtLeastOrStrongerThan(ordering, AtomicOrdering::Acquire) )
 453                         return true;
 454         }
 455
 456         return false;
 457 }
 458
 459 void CDSPass::chooseInstructionsToInstrument(
 460         SmallVectorImpl<Instruction *> &Local, SmallVectorImpl<Instruction *> &All,
 461         const DataLayout &DL) {
 462         SmallPtrSet<Value*, 8> WriteTargets;
 463         // Iterate from the end.
 464         for (Instruction *I : reverse(Local)) {
 465                 if (StoreInst *Store = dyn_cast<StoreInst>(I)) {
 466                         Value *Addr = Store->getPointerOperand();
 467                         if (!shouldInstrumentReadWriteFromAddress(I->getModule(), Addr))
 468                                 continue;
 469                         WriteTargets.insert(Addr);
 470                 } else {
 471                         LoadInst *Load = cast<LoadInst>(I);
 472                         Value *Addr = Load->getPointerOperand();
 473                         if (!shouldInstrumentReadWriteFromAddress(I->getModule(), Addr))
 474                                 continue;
 475                         if (WriteTargets.count(Addr)) {
 476                                 // We will write to this temp, so no reason to analyze the read.
 477                                 NumOmittedReadsBeforeWrite++;
 478                                 continue;
 479                         }
 480                         if (addrPointsToConstantData(Addr)) {
 481                                 // Addr points to some constant data -- it can not race with any writes.
 482                                 continue;
 483                         }
 484                 }
 485                 Value *Addr = isa<StoreInst>(*I)
 486                         ? cast<StoreInst>(I)->getPointerOperand()
 487                         : cast<LoadInst>(I)->getPointerOperand();
 488                 if (isa<AllocaInst>(GetUnderlyingObject(Addr, DL)) &&
 489                                 !PointerMayBeCaptured(Addr, true, true)) {
 490                         // The variable is addressable but not captured, so it cannot be
 491                         // referenced from a different thread and participate in a data race
 492                         // (see llvm/Analysis/CaptureTracking.h for details).
 493                         NumOmittedNonCaptured++;
 494                         continue;
 495                 }
 496                 All.push_back(I);
 497         }
 498         Local.clear();
 499 }
 500
 501 /* Not implemented
 502 void CDSPass::InsertRuntimeIgnores(Function &F) {
 503         IRBuilder<> IRB(F.getEntryBlock().getFirstNonPHI());
 504         IRB.CreateCall(CDSIgnoreBegin);
 505         EscapeEnumerator EE(F, "cds_ignore_cleanup", ClHandleCxxExceptions);
 506         while (IRBuilder<> *AtExit = EE.Next()) {
 507                 AtExit->CreateCall(CDSIgnoreEnd);
 508         }
 509 }*/
 510
 511 bool CDSPass::runOnFunction(Function &F) {
 512         initializeCallbacks( *F.getParent() );
 513         SmallVector<Instruction*, 8> AllLoadsAndStores;
 514         SmallVector<Instruction*, 8> LocalLoadsAndStores;
 515         SmallVector<Instruction*, 8> VolatileLoadsAndStores;
 516         SmallVector<Instruction*, 8> AtomicAccesses;
 517         SmallVector<Instruction*, 8> MemIntrinCalls;
 518
 519         bool Res = false;
 520         bool HasAtomic = false;
 521         bool HasVolatile = false;
 522         const DataLayout &DL = F.getParent()->getDataLayout();
 523
 524         // instrumentLoops(F);
 525
 526         for (auto &BB : F) {
 527                 for (auto &Inst : BB) {
 528                         if ( (&Inst)->isAtomic() ) {
 529                                 AtomicAccesses.push_back(&Inst);
 530                                 HasAtomic = true;
 531
 532                                 if (shouldInstrumentBeforeAtomics(&Inst)) {
 533                                         chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores,
 534                                                 DL);
 535                                 }
 536                         } /*else if (isAtomicCall(&Inst) ) {
 537                                 AtomicAccesses.push_back(&Inst);
 538                                 HasAtomic = true;
 539                                 chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores,
 540                                         DL);
 541                         }*/ else if (isa<LoadInst>(Inst) || isa<StoreInst>(Inst)) {
 542                                 LoadInst *LI = dyn_cast<LoadInst>(&Inst);
 543                                 StoreInst *SI = dyn_cast<StoreInst>(&Inst);
 544                                 bool isVolatile = ( LI ? LI->isVolatile() : SI->isVolatile() );
 545
 546                                 if (isVolatile) {
 547                                         VolatileLoadsAndStores.push_back(&Inst);
 548                                         HasVolatile = true;
 549                                 } else
 550                                         LocalLoadsAndStores.push_back(&Inst);
 551                         } else if (isa<CallInst>(Inst) || isa<InvokeInst>(Inst)) {
 552                                 if (isa<MemIntrinsic>(Inst))
 553                                         MemIntrinCalls.push_back(&Inst);
 554
 555                                 /*if (CallInst *CI = dyn_cast<CallInst>(&Inst))
 556                                         maybeMarkSanitizerLibraryCallNoBuiltin(CI, TLI);
 557                                 */
 558
 559                                 chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores,
 560                                         DL);
 561                         }
 562                 }
 563
 564                 chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores, DL);
 565         }
 566
 567         for (auto Inst : AllLoadsAndStores) {
 568                 Res |= instrumentLoadOrStore(Inst, DL);
 569         }
 570
 571         for (auto Inst : VolatileLoadsAndStores) {
 572                 Res |= instrumentVolatile(Inst, DL);
 573         }
 574
 575         for (auto Inst : AtomicAccesses) {
 576                 Res |= instrumentAtomic(Inst, DL);
 577         }
 578
 579         for (auto Inst : MemIntrinCalls) {
 580                 Res |= instrumentMemIntrinsic(Inst);
 581         }
 582
 583         // Instrument function entry and exit for functions containing atomics or volatiles
 584         if (Res && ( HasAtomic || HasVolatile) ) {
 585                 IRBuilder<> IRB(F.getEntryBlock().getFirstNonPHI());
 586                 /* Unused for now
 587                 Value *ReturnAddress = IRB.CreateCall(
 588                         Intrinsic::getDeclaration(F.getParent(), Intrinsic::returnaddress),
 589                         IRB.getInt32(0));
 590                 */
 591
 592                 Value * FuncName = IRB.CreateGlobalStringPtr(F.getName());
 593                 IRB.CreateCall(CDSFuncEntry, FuncName);
 594
 595                 EscapeEnumerator EE(F, "cds_cleanup", true);
 596                 while (IRBuilder<> *AtExit = EE.Next()) {
 597                   AtExit->CreateCall(CDSFuncExit, FuncName);
 598                 }
 599
 600                 Res = true;
 601         }
 602
 603         return false;
 604 }
 605
 606 bool CDSPass::instrumentLoadOrStore(Instruction *I,
 607                                                                         const DataLayout &DL) {
 608         IRBuilder<> IRB(I);
 609         bool IsWrite = isa<StoreInst>(*I);
 610         Value *Addr = IsWrite
 611                 ? cast<StoreInst>(I)->getPointerOperand()
 612                 : cast<LoadInst>(I)->getPointerOperand();
 613
 614         // swifterror memory addresses are mem2reg promoted by instruction selection.
 615         // As such they cannot have regular uses like an instrumentation function and
 616         // it makes no sense to track them as memory.
 617         if (Addr->isSwiftError())
 618                 return false;
 619
 620         int Idx = getMemoryAccessFuncIndex(Addr, DL);
 621         if (Idx < 0)
 622                 return false;
 623
 624         if (IsWrite && isVtableAccess(I)) {
 625                 /* TODO
 626                 LLVM_DEBUG(dbgs() << "  VPTR : " << *I << "\n");
 627                 Value *StoredValue = cast<StoreInst>(I)->getValueOperand();
 628                 // StoredValue may be a vector type if we are storing several vptrs at once.
 629                 // In this case, just take the first element of the vector since this is
 630                 // enough to find vptr races.
 631                 if (isa<VectorType>(StoredValue->getType()))
 632                         StoredValue = IRB.CreateExtractElement(
 633                                         StoredValue, ConstantInt::get(IRB.getInt32Ty(), 0));
 634                 if (StoredValue->getType()->isIntegerTy())
 635                         StoredValue = IRB.CreateIntToPtr(StoredValue, IRB.getInt8PtrTy());
 636                 // Call TsanVptrUpdate.
 637                 IRB.CreateCall(TsanVptrUpdate,
 638                                                 {IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()),
 639                                                         IRB.CreatePointerCast(StoredValue, IRB.getInt8PtrTy())});
 640                 NumInstrumentedVtableWrites++;
 641                 */
 642                 return true;
 643         }
 644
 645         if (!IsWrite && isVtableAccess(I)) {
 646                 /* TODO
 647                 IRB.CreateCall(TsanVptrLoad,
 648                                                  IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()));
 649                 NumInstrumentedVtableReads++;
 650                 */
 651                 return true;
 652         }
 653
 654         // TODO: unaligned reads and writes
 655         Value *OnAccessFunc = nullptr;
 656         OnAccessFunc = IsWrite ? CDSStore[Idx] : CDSLoad[Idx];
 657         IRB.CreateCall(OnAccessFunc, IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()));
 658         if (IsWrite) NumInstrumentedWrites++;
 659         else         NumInstrumentedReads++;
 660         return true;
 661 }
 662
 663 bool CDSPass::instrumentVolatile(Instruction * I, const DataLayout &DL) {
 664         IRBuilder<> IRB(I);
 665         Value *position = getPosition(I, IRB);
 666
 667         if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
 668                 Value *Addr = LI->getPointerOperand();
 669                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 670                 if (Idx < 0)
 671                         return false;
 672                 const unsigned ByteSize = 1U << Idx;
 673                 const unsigned BitSize = ByteSize * 8;
 674                 Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
 675                 Type *PtrTy = Ty->getPointerTo();
 676                 Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy), position};
 677
 678                 Type *OrigTy = cast<PointerType>(Addr->getType())->getElementType();
 679                 Value *C = IRB.CreateCall(CDSVolatileLoad[Idx], Args);
 680                 Value *Cast = IRB.CreateBitOrPointerCast(C, OrigTy);
 681                 I->replaceAllUsesWith(Cast);
 682         } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
 683                 Value *Addr = SI->getPointerOperand();
 684                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 685                 if (Idx < 0)
 686                         return false;
 687                 const unsigned ByteSize = 1U << Idx;
 688                 const unsigned BitSize = ByteSize * 8;
 689                 Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
 690                 Type *PtrTy = Ty->getPointerTo();
 691                 Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
 692                                           IRB.CreateBitOrPointerCast(SI->getValueOperand(), Ty),
 693                                           position};
 694                 CallInst *C = CallInst::Create(CDSVolatileStore[Idx], Args);
 695                 ReplaceInstWithInst(I, C);
 696         } else {
 697                 return false;
 698         }
 699
 700         return true;
 701 }
 702
 703 bool CDSPass::instrumentMemIntrinsic(Instruction *I) {
 704         IRBuilder<> IRB(I);
 705         if (MemSetInst *M = dyn_cast<MemSetInst>(I)) {
 706                 IRB.CreateCall(
 707                         MemsetFn,
 708                         {IRB.CreatePointerCast(M->getArgOperand(0), IRB.getInt8PtrTy()),
 709                          IRB.CreateIntCast(M->getArgOperand(1), IRB.getInt32Ty(), false),
 710                          IRB.CreateIntCast(M->getArgOperand(2), IntPtrTy, false)});
 711                 I->eraseFromParent();
 712         } else if (MemTransferInst *M = dyn_cast<MemTransferInst>(I)) {
 713                 IRB.CreateCall(
 714                         isa<MemCpyInst>(M) ? MemcpyFn : MemmoveFn,
 715                         {IRB.CreatePointerCast(M->getArgOperand(0), IRB.getInt8PtrTy()),
 716                          IRB.CreatePointerCast(M->getArgOperand(1), IRB.getInt8PtrTy()),
 717                          IRB.CreateIntCast(M->getArgOperand(2), IntPtrTy, false)});
 718                 I->eraseFromParent();
 719         }
 720         return false;
 721 }
 722
 723 bool CDSPass::instrumentAtomic(Instruction * I, const DataLayout &DL) {
 724         IRBuilder<> IRB(I);
 725         Value *position = getPosition(I, IRB);
 726
 727 /*
 728         if (auto *CI = dyn_cast<CallInst>(I)) {
 729                 return instrumentAtomicCall(CI, DL);
 730         }
 731 */
 732
 733         if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
 734                 Value *Addr = LI->getPointerOperand();
 735                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 736                 if (Idx < 0)
 737                         return false;
 738
 739                 int atomic_order_index = getAtomicOrderIndex(LI->getOrdering());
 740                 Value *order = ConstantInt::get(OrdTy, atomic_order_index);
 741                 Value *Args[] = {Addr, order, position};
 742                 Instruction* funcInst = CallInst::Create(CDSAtomicLoad[Idx], Args);
 743                 ReplaceInstWithInst(LI, funcInst);
 744         } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
 745                 Value *Addr = SI->getPointerOperand();
 746                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 747                 if (Idx < 0)
 748                         return false;
 749
 750                 int atomic_order_index = getAtomicOrderIndex(SI->getOrdering());
 751                 Value *val = SI->getValueOperand();
 752                 Value *order = ConstantInt::get(OrdTy, atomic_order_index);
 753                 Value *Args[] = {Addr, val, order, position};
 754                 Instruction* funcInst = CallInst::Create(CDSAtomicStore[Idx], Args);
 755                 ReplaceInstWithInst(SI, funcInst);
 756         } else if (AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I)) {
 757                 Value *Addr = RMWI->getPointerOperand();
 758                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 759                 if (Idx < 0)
 760                         return false;
 761
 762                 int atomic_order_index = getAtomicOrderIndex(RMWI->getOrdering());
 763                 Value *val = RMWI->getValOperand();
 764                 Value *order = ConstantInt::get(OrdTy, atomic_order_index);
 765                 Value *Args[] = {Addr, val, order, position};
 766                 Instruction* funcInst = CallInst::Create(CDSAtomicRMW[RMWI->getOperation()][Idx], Args);
 767                 ReplaceInstWithInst(RMWI, funcInst);
 768         } else if (AtomicCmpXchgInst *CASI = dyn_cast<AtomicCmpXchgInst>(I)) {
 769                 IRBuilder<> IRB(CASI);
 770
 771                 Value *Addr = CASI->getPointerOperand();
 772                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 773                 if (Idx < 0)
 774                         return false;
 775
 776                 const unsigned ByteSize = 1U << Idx;
 777                 const unsigned BitSize = ByteSize * 8;
 778                 Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
 779                 Type *PtrTy = Ty->getPointerTo();
 780
 781                 Value *CmpOperand = IRB.CreateBitOrPointerCast(CASI->getCompareOperand(), Ty);
 782                 Value *NewOperand = IRB.CreateBitOrPointerCast(CASI->getNewValOperand(), Ty);
 783
 784                 int atomic_order_index_succ = getAtomicOrderIndex(CASI->getSuccessOrdering());
 785                 int atomic_order_index_fail = getAtomicOrderIndex(CASI->getFailureOrdering());
 786                 Value *order_succ = ConstantInt::get(OrdTy, atomic_order_index_succ);
 787                 Value *order_fail = ConstantInt::get(OrdTy, atomic_order_index_fail);
 788
 789                 Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
 790                                                  CmpOperand, NewOperand,
 791                                                  order_succ, order_fail, position};
 792
 793                 CallInst *funcInst = IRB.CreateCall(CDSAtomicCAS_V1[Idx], Args);
 794                 Value *Success = IRB.CreateICmpEQ(funcInst, CmpOperand);
 795
 796                 Value *OldVal = funcInst;
 797                 Type *OrigOldValTy = CASI->getNewValOperand()->getType();
 798                 if (Ty != OrigOldValTy) {
 799                         // The value is a pointer, so we need to cast the return value.
 800                         OldVal = IRB.CreateIntToPtr(funcInst, OrigOldValTy);
 801                 }
 802
 803                 Value *Res =
 804                   IRB.CreateInsertValue(UndefValue::get(CASI->getType()), OldVal, 0);
 805                 Res = IRB.CreateInsertValue(Res, Success, 1);
 806
 807                 I->replaceAllUsesWith(Res);
 808                 I->eraseFromParent();
 809         } else if (FenceInst *FI = dyn_cast<FenceInst>(I)) {
 810                 int atomic_order_index = getAtomicOrderIndex(FI->getOrdering());
 811                 Value *order = ConstantInt::get(OrdTy, atomic_order_index);
 812                 Value *Args[] = {order, position};
 813
 814                 CallInst *funcInst = CallInst::Create(CDSAtomicThreadFence, Args);
 815                 ReplaceInstWithInst(FI, funcInst);
 816                 // errs() << "Thread Fences replaced\n";
 817         }
 818         return true;
 819 }
 820
 821 bool CDSPass::isAtomicCall(Instruction *I) {
 822         if ( auto *CI = dyn_cast<CallInst>(I) ) {
 823                 Function *fun = CI->getCalledFunction();
 824                 if (fun == NULL)
 825                         return false;
 826
 827                 StringRef funName = fun->getName();
 828
 829                 // TODO: come up with better rules for function name checking
 830                 for (StringRef name : AtomicFuncNames) {
 831                         if ( funName.contains(name) )
 832                                 return true;
 833                 }
 834
 835                 for (StringRef PartialName : PartialAtomicFuncNames) {
 836                         if (funName.contains(PartialName) &&
 837                                         funName.contains("atomic") )
 838                                 return true;
 839                 }
 840         }
 841
 842         return false;
 843 }
 844
 845 bool CDSPass::instrumentAtomicCall(CallInst *CI, const DataLayout &DL) {
 846         IRBuilder<> IRB(CI);
 847         Function *fun = CI->getCalledFunction();
 848         StringRef funName = fun->getName();
 849         std::vector<Value *> parameters;
 850
 851         User::op_iterator begin = CI->arg_begin();
 852         User::op_iterator end = CI->arg_end();
 853         for (User::op_iterator it = begin; it != end; ++it) {
 854                 Value *param = *it;
 855                 parameters.push_back(param);
 856         }
 857
 858         // obtain source line number of the CallInst
 859         Value *position = getPosition(CI, IRB);
 860
 861         // the pointer to the address is always the first argument
 862         Value *OrigPtr = parameters[0];
 863
 864         int Idx = getMemoryAccessFuncIndex(OrigPtr, DL);
 865         if (Idx < 0)
 866                 return false;
 867
 868         const unsigned ByteSize = 1U << Idx;
 869         const unsigned BitSize = ByteSize * 8;
 870         Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
 871         Type *PtrTy = Ty->getPointerTo();
 872
 873         // atomic_init; args = {obj, order}
 874         if (funName.contains("atomic_init")) {
 875                 Value *OrigVal = parameters[1];
 876
 877                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 878                 Value *val;
 879                 if (OrigVal->getType()->isPtrOrPtrVectorTy())
 880                         val = IRB.CreatePointerCast(OrigVal, Ty);
 881                 else
 882                         val = IRB.CreateIntCast(OrigVal, Ty, true);
 883
 884                 Value *args[] = {ptr, val, position};
 885
 886                 if (!checkSignature(CDSAtomicInit[Idx], args))
 887                         return false;
 888
 889                 Instruction* funcInst = CallInst::Create(CDSAtomicInit[Idx], args);
 890                 ReplaceInstWithInst(CI, funcInst);
 891                 return true;
 892         }
 893
 894         // atomic_load; args = {obj, order}
 895         if (funName.contains("atomic_load")) {
 896                 bool isExplicit = funName.contains("atomic_load_explicit");
 897
 898                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 899                 Value *order;
 900                 if (isExplicit)
 901                         order = IRB.CreateBitOrPointerCast(parameters[1], OrdTy);
 902                 else
 903                         order = ConstantInt::get(OrdTy,
 904                                                         (int) AtomicOrderingCABI::seq_cst);
 905                 Value *args[] = {ptr, order, position};
 906
 907                 if (!checkSignature(CDSAtomicLoad[Idx], args))
 908                         return false;
 909
 910                 Instruction* funcInst = CallInst::Create(CDSAtomicLoad[Idx], args);
 911                 ReplaceInstWithInst(CI, funcInst);
 912
 913                 return true;
 914         } else if (funName.contains("atomic") &&
 915                                         funName.contains("load") ) {
 916                 // does this version of call always have an atomic order as an argument?
 917                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 918                 Value *order = IRB.CreateBitOrPointerCast(parameters[1], OrdTy);
 919                 Value *args[] = {ptr, order, position};
 920
 921                 // Without this check, gdax does not compile :(
 922                 if (!CI->getType()->isPointerTy()) {
 923                         return false;
 924                 }
 925
 926                 if (!checkSignature(CDSAtomicLoad[Idx], args))
 927                         return false;
 928
 929                 CallInst *funcInst = IRB.CreateCall(CDSAtomicLoad[Idx], args);
 930                 Value *RetVal = IRB.CreateIntToPtr(funcInst, CI->getType());
 931
 932                 CI->replaceAllUsesWith(RetVal);
 933                 CI->eraseFromParent();
 934
 935                 return true;
 936         }
 937
 938         // atomic_store; args = {obj, val, order}
 939         if (funName.contains("atomic_store")) {
 940                 bool isExplicit = funName.contains("atomic_store_explicit");
 941                 Value *OrigVal = parameters[1];
 942
 943                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 944                 Value *val = IRB.CreatePointerCast(OrigVal, Ty);
 945                 Value *order;
 946                 if (isExplicit)
 947                         order = IRB.CreateBitOrPointerCast(parameters[2], OrdTy);
 948                 else
 949                         order = ConstantInt::get(OrdTy,
 950                                                         (int) AtomicOrderingCABI::seq_cst);
 951                 Value *args[] = {ptr, val, order, position};
 952
 953                 if (!checkSignature(CDSAtomicStore[Idx], args))
 954                         return false;
 955
 956                 Instruction* funcInst = CallInst::Create(CDSAtomicStore[Idx], args);
 957                 ReplaceInstWithInst(CI, funcInst);
 958
 959                 return true;
 960         } else if (funName.contains("atomic") &&
 961                                         funName.contains("store") ) {
 962                 // Does this version of call always have an atomic order as an argument?
 963                 if (parameters.size() < 3)
 964                         return false;
 965
 966                 Value *OrigVal = parameters[1];
 967                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 968
 969                 Value *val;
 970                 if (OrigVal->getType()->isPtrOrPtrVectorTy())
 971                         val = IRB.CreatePointerCast(OrigVal, Ty);
 972                 else
 973                         val = IRB.CreateIntCast(OrigVal, Ty, true);
 974
 975                 Value *order = IRB.CreateBitOrPointerCast(parameters[2], OrdTy);
 976                 Value *args[] = {ptr, val, order, position};
 977
 978                 if (!checkSignature(CDSAtomicStore[Idx], args))
 979                         return false;
 980
 981                 Instruction* funcInst = CallInst::Create(CDSAtomicStore[Idx], args);
 982                 ReplaceInstWithInst(CI, funcInst);
 983
 984                 return true;
 985         }
 986
 987         // atomic_fetch_*; args = {obj, val, order}
 988         if (funName.contains("atomic_fetch_") ||
 989                 funName.contains("atomic_exchange")) {
 990
 991                 bool isExplicit = funName.contains("_explicit");
 992                 Value *OrigVal = parameters[1];
 993
 994                 int op;
 995                 if ( funName.contains("_fetch_add") )
 996                         op = AtomicRMWInst::Add;
 997                 else if ( funName.contains("_fetch_sub") )
 998                         op = AtomicRMWInst::Sub;
 999                 else if ( funName.contains("_fetch_and") )
1000                         op = AtomicRMWInst::And;
1001                 else if ( funName.contains("_fetch_or") )
1002                         op = AtomicRMWInst::Or;
1003                 else if ( funName.contains("_fetch_xor") )
1004                         op = AtomicRMWInst::Xor;
1005                 else if ( funName.contains("atomic_exchange") )
1006                         op = AtomicRMWInst::Xchg;
1007                 else {
1008                         errs() << "Unknown atomic read-modify-write operation\n";
1009                         return false;
1010                 }
1011
1012                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
1013                 Value *val;
1014                 if (OrigVal->getType()->isPtrOrPtrVectorTy())
1015                         val = IRB.CreatePointerCast(OrigVal, Ty);
1016                 else
1017                         val = IRB.CreateIntCast(OrigVal, Ty, true);
1018
1019                 Value *order;
1020                 if (isExplicit)
1021                         order = IRB.CreateBitOrPointerCast(parameters[2], OrdTy);
1022                 else
1023                         order = ConstantInt::get(OrdTy,
1024                                                         (int) AtomicOrderingCABI::seq_cst);
1025                 Value *args[] = {ptr, val, order, position};
1026
1027                 if (!checkSignature(CDSAtomicRMW[op][Idx], args))
1028                         return false;
1029
1030                 Instruction* funcInst = CallInst::Create(CDSAtomicRMW[op][Idx], args);
1031                 ReplaceInstWithInst(CI, funcInst);
1032
1033                 return true;
1034         } else if (funName.contains("fetch")) {
1035                 errs() << "atomic fetch captured. Not implemented yet. ";
1036                 errs() << "See source file :";
1037                 getPosition(CI, IRB, true);
1038                 return false;
1039         } else if (funName.contains("exchange") &&
1040                         !funName.contains("compare_exchange") ) {
1041                 if (CI->getType()->isPointerTy()) {
1042                         /**
1043                          * TODO: instrument the following case
1044                          * mcs-lock.h
1045                          * std::atomic<struct T *> m_tail;
1046                          * struct T * me;
1047                          * struct T * pred = m_tail.exchange(me, memory_order_*);
1048                          */
1049                         errs() << "atomic exchange captured. Not implemented yet. ";
1050                         errs() << "See source file :";
1051                         getPosition(CI, IRB, true);
1052
1053                         return false;
1054                 }
1055
1056                 Value *OrigVal = parameters[1];
1057
1058                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
1059                 Value *val;
1060                 if (OrigVal->getType()->isPtrOrPtrVectorTy())
1061                         val = IRB.CreatePointerCast(OrigVal, Ty);
1062                 else
1063                         val = IRB.CreateIntCast(OrigVal, Ty, true);
1064
1065                 Value *order = IRB.CreateBitOrPointerCast(parameters[2], OrdTy);
1066                 Value *args[] = {ptr, val, order, position};
1067
1068                 int op = AtomicRMWInst::Xchg;
1069
1070                 if (!checkSignature(CDSAtomicRMW[op][Idx], args))
1071                         return false;
1072
1073                 Instruction* funcInst = CallInst::Create(CDSAtomicRMW[op][Idx], args);
1074                 ReplaceInstWithInst(CI, funcInst);
1075
1076                 return true;
1077         }
1078
1079         /* atomic_compare_exchange_*;
1080            args = {obj, expected, new value, order1, order2}
1081         */
1082         if ( funName.contains("atomic_compare_exchange_") ) {
1083                 bool isExplicit = funName.contains("_explicit");
1084
1085                 Value *Addr = IRB.CreatePointerCast(OrigPtr, PtrTy);
1086                 Value *CmpOperand = IRB.CreatePointerCast(parameters[1], PtrTy);
1087                 Value *NewOperand = IRB.CreateBitOrPointerCast(parameters[2], Ty);
1088
1089                 Value *order_succ, *order_fail;
1090                 if (isExplicit) {
1091                         order_succ = IRB.CreateBitOrPointerCast(parameters[3], OrdTy);
1092
1093                         if (parameters.size() > 4) {
1094                                 order_fail = IRB.CreateBitOrPointerCast(parameters[4], OrdTy);
1095                         } else {
1096                                 /* The failure order is not provided */
1097                                 order_fail = order_succ;
1098                                 ConstantInt * order_succ_cast = dyn_cast<ConstantInt>(order_succ);
1099                                 int index = order_succ_cast->getSExtValue();
1100
1101                                 order_fail = ConstantInt::get(OrdTy,
1102                                                                 AtomicCasFailureOrderIndex(index));
1103                         }
1104                 } else  {
1105                         order_succ = ConstantInt::get(OrdTy,
1106                                                         (int) AtomicOrderingCABI::seq_cst);
1107                         order_fail = ConstantInt::get(OrdTy,
1108                                                         (int) AtomicOrderingCABI::seq_cst);
1109                 }
1110
1111                 Value *args[] = {Addr, CmpOperand, NewOperand,
1112                                                         order_succ, order_fail, position};
1113
1114                 if (!checkSignature(CDSAtomicCAS_V2[Idx], args))
1115                         return false;
1116
1117                 Instruction* funcInst = CallInst::Create(CDSAtomicCAS_V2[Idx], args);
1118                 ReplaceInstWithInst(CI, funcInst);
1119
1120                 return true;
1121         } else if ( funName.contains("compare_exchange_strong") ||
1122                                 funName.contains("compare_exchange_weak") ) {
1123                 Value *Addr = IRB.CreatePointerCast(OrigPtr, PtrTy);
1124                 Value *CmpOperand = IRB.CreatePointerCast(parameters[1], PtrTy);
1125                 Value *NewOperand = IRB.CreateBitOrPointerCast(parameters[2], Ty);
1126
1127                 Value *order_succ, *order_fail;
1128                 order_succ = IRB.CreateBitOrPointerCast(parameters[3], OrdTy);
1129
1130                 if (parameters.size() > 4) {
1131                         order_fail = IRB.CreateBitOrPointerCast(parameters[4], OrdTy);
1132                 } else {
1133                         /* The failure order is not provided */
1134                         order_fail = order_succ;
1135                         ConstantInt * order_succ_cast = dyn_cast<ConstantInt>(order_succ);
1136                         int index = order_succ_cast->getSExtValue();
1137
1138                         order_fail = ConstantInt::get(OrdTy,
1139                                                         AtomicCasFailureOrderIndex(index));
1140                 }
1141
1142                 Value *args[] = {Addr, CmpOperand, NewOperand,
1143                                                         order_succ, order_fail, position};
1144
1145                 if (!checkSignature(CDSAtomicCAS_V2[Idx], args))
1146                         return false;
1147
1148                 Instruction* funcInst = CallInst::Create(CDSAtomicCAS_V2[Idx], args);
1149                 ReplaceInstWithInst(CI, funcInst);
1150
1151                 return true;
1152         }
1153
1154         return false;
1155 }
1156
1157 int CDSPass::getMemoryAccessFuncIndex(Value *Addr,
1158                                                                                 const DataLayout &DL) {
1159         Type *OrigPtrTy = Addr->getType();
1160         Type *OrigTy = cast<PointerType>(OrigPtrTy)->getElementType();
1161         assert(OrigTy->isSized());
1162         uint32_t TypeSize = DL.getTypeStoreSizeInBits(OrigTy);
1163         if (TypeSize != 8  && TypeSize != 16 &&
1164                 TypeSize != 32 && TypeSize != 64 && TypeSize != 128) {
1165                 NumAccessesWithBadSize++;
1166                 // Ignore all unusual sizes.
1167                 return -1;
1168         }
1169         size_t Idx = countTrailingZeros(TypeSize / 8);
1170         //assert(Idx < kNumberOfAccessSizes);
1171         if (Idx >= kNumberOfAccessSizes) {
1172                 return -1;
1173         }
1174         return Idx;
1175 }
1176
1177 bool CDSPass::instrumentLoops(Function &F)
1178 {
1179         DominatorTree DT(F);
1180         LoopInfo LI(DT);
1181
1182         SmallVector<Loop *, 4> Loops = LI.getLoopsInPreorder();
1183         bool instrumented = false;
1184
1185         // Do a post-order traversal of the loops so that counter updates can be
1186         // iteratively hoisted outside the loop nest.
1187         for (auto *Loop : llvm::reverse(Loops)) {
1188                 bool instrument_loop = false;
1189
1190                 // Iterator over loop blocks and search for atomics and volatiles
1191                 Loop::block_iterator it;
1192                 for (it = Loop->block_begin(); it != Loop->block_end(); it++) {
1193                         BasicBlock * block = *it;
1194                         for (auto &Inst : *block) {
1195                                 if ( (&Inst)->isAtomic() ) {
1196                                         instrument_loop = true;
1197                                         break;
1198                                 } else if (isAtomicCall(&Inst)) {
1199                                         instrument_loop = true;
1200                                         break;
1201                                 } else if (isa<LoadInst>(Inst) || isa<StoreInst>(Inst)) {
1202                                         LoadInst *LI = dyn_cast<LoadInst>(&Inst);
1203                                         StoreInst *SI = dyn_cast<StoreInst>(&Inst);
1204                                         bool isVolatile = ( LI ? LI->isVolatile() : SI->isVolatile() );
1205
1206                                         if (isVolatile) {
1207                                                 instrument_loop = true;
1208                                                 break;
1209                                         }
1210                                 }
1211                         }
1212
1213                         if (instrument_loop)
1214                                 break;
1215                 }
1216
1217                 if (instrument_loop) {
1218                         // TODO: what to instrument?
1219                         errs() << "Function: " << F.getName() << "\n";
1220                         BasicBlock * header = Loop->getHeader();
1221                         header->dump();
1222
1223                         instrumented = true;
1224                 }
1225         }
1226
1227         return instrumented;
1228 }
1229
1230 char CDSPass::ID = 0;
1231
1232 // Automatically enable the pass.
1233 static void registerCDSPass(const PassManagerBuilder &,
1234                                                         legacy::PassManagerBase &PM) {
1235         PM.add(new CDSPass());
1236 }
1237
1238 /* Enable the pass when opt level is greater than 0 */
1239 static RegisterStandardPasses
1240         RegisterMyPass1(PassManagerBuilder::EP_OptimizerLast,
1241 registerCDSPass);
1242
1243 /* Enable the pass when opt level is 0 */
1244 static RegisterStandardPasses
1245         RegisterMyPass2(PassManagerBuilder::EP_EnabledOnOptLevel0,
1246 registerCDSPass);