C++ LoadInst::setAtomic方法代码示例

extern "C" LLVMValueRef
LLVMRustBuildAtomicLoad(LLVMBuilderRef B, LLVMValueRef Source, const char *Name,
                        LLVMAtomicOrdering Order, unsigned Alignment) {
  LoadInst *LI = new LoadInst(unwrap(Source), 0);
  LI->setAtomic(fromRust(Order));
  LI->setAlignment(Alignment);
  return wrap(unwrap(B)->Insert(LI, Name));
}

/// InstCombineLoadCast - Fold 'load (cast P)' -> cast (load P)' when possible.
static Instruction *InstCombineLoadCast(InstCombiner &IC, LoadInst &LI,
                                        const DataLayout *DL) {
  User *CI = cast<User>(LI.getOperand(0));
  Value *CastOp = CI->getOperand(0);

  PointerType *DestTy = cast<PointerType>(CI->getType());
  Type *DestPTy = DestTy->getElementType();
  if (PointerType *SrcTy = dyn_cast<PointerType>(CastOp->getType())) {

    // If the address spaces don't match, don't eliminate the cast.
    if (DestTy->getAddressSpace() != SrcTy->getAddressSpace())
      return 0;

    Type *SrcPTy = SrcTy->getElementType();

    if (DestPTy->isIntegerTy() || DestPTy->isPointerTy() ||
         DestPTy->isVectorTy()) {
      // If the source is an array, the code below will not succeed.  Check to
      // see if a trivial 'gep P, 0, 0' will help matters.  Only do this for
      // constants.
      if (ArrayType *ASrcTy = dyn_cast<ArrayType>(SrcPTy))
        if (Constant *CSrc = dyn_cast<Constant>(CastOp))
          if (ASrcTy->getNumElements() != 0) {
            Type *IdxTy = DL
                        ? DL->getIntPtrType(SrcTy)
                        : Type::getInt64Ty(SrcTy->getContext());
            Value *Idx = Constant::getNullValue(IdxTy);
            Value *Idxs[2] = { Idx, Idx };
            CastOp = ConstantExpr::getGetElementPtr(CSrc, Idxs);
            SrcTy = cast<PointerType>(CastOp->getType());
            SrcPTy = SrcTy->getElementType();
          }

      if (IC.getDataLayout() &&
          (SrcPTy->isIntegerTy() || SrcPTy->isPointerTy() ||
            SrcPTy->isVectorTy()) &&
          // Do not allow turning this into a load of an integer, which is then
          // casted to a pointer, this pessimizes pointer analysis a lot.
          (SrcPTy->isPtrOrPtrVectorTy() ==
           LI.getType()->isPtrOrPtrVectorTy()) &&
          IC.getDataLayout()->getTypeSizeInBits(SrcPTy) ==
               IC.getDataLayout()->getTypeSizeInBits(DestPTy)) {

        // Okay, we are casting from one integer or pointer type to another of
        // the same size.  Instead of casting the pointer before the load, cast
        // the result of the loaded value.
        LoadInst *NewLoad =
          IC.Builder->CreateLoad(CastOp, LI.isVolatile(), CI->getName());
        NewLoad->setAlignment(LI.getAlignment());
        NewLoad->setAtomic(LI.getOrdering(), LI.getSynchScope());
        // Now cast the result of the load.
        return new BitCastInst(NewLoad, LI.getType());
      }
    }
  }
  return 0;
}

extern "C" LLVMValueRef LLVMBuildAtomicLoad(LLVMBuilderRef B,
                                            LLVMValueRef source,
                                            const char* Name,
                                            AtomicOrdering order,
                                            unsigned alignment) {
    LoadInst* li = new LoadInst(unwrap(source),0);
    li->setAtomic(order);
    li->setAlignment(alignment);
    return wrap(unwrap(B)->Insert(li, Name));
}

extern "C" LLVMValueRef LLVMBuildAtomicLoad(LLVMBuilderRef B,
                                            LLVMValueRef source,
                                            const char* Name,
                                            AtomicOrdering order) {
    LoadInst* li = new LoadInst(unwrap(source),0);
    li->setVolatile(true);
    li->setAtomic(order);
    li->setAlignment(sizeof(intptr_t));
    return wrap(unwrap(B)->Insert(li, Name));
}

void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F,
                                                    BasicBlock &BB) {
  BasicBlock::iterator IP = BB.getFirstInsertionPt(), BE = BB.end();
  // Skip static allocas at the top of the entry block so they don't become
  // dynamic when we split the block.  If we used our optimized stack layout,
  // then there will only be one alloca and it will come first.
  for (; IP != BE; ++IP) {
    AllocaInst *AI = dyn_cast<AllocaInst>(IP);
    if (!AI || !AI->isStaticAlloca())
      break;
  }

  bool IsEntryBB = &BB == &F.getEntryBlock();
  DebugLoc EntryLoc =
      IsEntryBB ? IP->getDebugLoc().getFnDebugLoc(*C) : IP->getDebugLoc();
  IRBuilder<> IRB(IP);
  IRB.SetCurrentDebugLocation(EntryLoc);
  SmallVector<Value *, 1> Indices;
  Value *GuardP = IRB.CreateAdd(
      IRB.CreatePointerCast(GuardArray, IntptrTy),
      ConstantInt::get(IntptrTy, (1 + SanCovFunction->getNumUses()) * 4));
  Type *Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty());
  GuardP = IRB.CreateIntToPtr(GuardP, Int32PtrTy);
  LoadInst *Load = IRB.CreateLoad(GuardP);
  Load->setAtomic(Monotonic);
  Load->setAlignment(4);
  Load->setMetadata(F.getParent()->getMDKindID("nosanitize"),
                    MDNode::get(*C, None));
  Value *Cmp = IRB.CreateICmpSGE(Constant::getNullValue(Load->getType()), Load);
  Instruction *Ins = SplitBlockAndInsertIfThen(
      Cmp, IP, false, MDBuilder(*C).createBranchWeights(1, 100000));
  IRB.SetInsertPoint(Ins);
  IRB.SetCurrentDebugLocation(EntryLoc);
  // __sanitizer_cov gets the PC of the instruction using GET_CALLER_PC.
  IRB.CreateCall(SanCovFunction, GuardP);
  IRB.CreateCall(EmptyAsm);  // Avoids callback merge.

  if (ClExperimentalTracing) {
    // Experimental support for tracing.
    // Insert a callback with the same guard variable as used for coverage.
    IRB.SetInsertPoint(IP);
    IRB.CreateCall(IsEntryBB ? SanCovTraceEnter : SanCovTraceBB, GuardP);
  }
}

void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
                                                    size_t Idx, bool UseCalls) {
  BasicBlock::iterator IP = BB.getFirstInsertionPt();
  bool IsEntryBB = &BB == &F.getEntryBlock();
  DebugLoc EntryLoc;
  if (IsEntryBB) {
    if (auto SP = F.getSubprogram())
      EntryLoc = DebugLoc::get(SP->getScopeLine(), 0, SP);
    // Keep static allocas and llvm.localescape calls in the entry block.  Even
    // if we aren't splitting the block, it's nice for allocas to be before
    // calls.
    IP = PrepareToSplitEntryBlock(BB, IP);
  } else {
    EntryLoc = IP->getDebugLoc();
  }

  IRBuilder<> IRB(&*IP);
  IRB.SetCurrentDebugLocation(EntryLoc);
  if (Options.TracePC) {
    IRB.CreateCall(SanCovTracePC); // gets the PC using GET_CALLER_PC.
    IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge.
  } else if (Options.TracePCGuard) {
    //auto GuardVar = new GlobalVariable(
    //   *F.getParent(), Int64Ty, false, GlobalVariable::LinkOnceODRLinkage,
    //    Constant::getNullValue(Int64Ty), "__sancov_guard." + F.getName());
    // if (auto Comdat = F.getComdat())
    //  GuardVar->setComdat(Comdat);
    // TODO: add debug into to GuardVar.
    // GuardVar->setSection(SanCovTracePCGuardSection);
    // auto GuardPtr = IRB.CreatePointerCast(GuardVar, IntptrPtrTy);
    auto GuardPtr = IRB.CreateIntToPtr(
        IRB.CreateAdd(IRB.CreatePointerCast(FunctionGuardArray, IntptrTy),
                      ConstantInt::get(IntptrTy, Idx * 4)),
        Int32PtrTy);
    if (!UseCalls) {
      auto GuardLoad = IRB.CreateLoad(GuardPtr);
      GuardLoad->setAtomic(AtomicOrdering::Monotonic);
      GuardLoad->setAlignment(8);
      SetNoSanitizeMetadata(GuardLoad);  // Don't instrument with e.g. asan.
      auto Cmp = IRB.CreateICmpNE(
          GuardLoad, Constant::getNullValue(GuardLoad->getType()));
      auto Ins = SplitBlockAndInsertIfThen(
          Cmp, &*IP, false, MDBuilder(*C).createBranchWeights(1, 100000));
      IRB.SetCurrentDebugLocation(EntryLoc);
      IRB.SetInsertPoint(Ins);
    }
    IRB.CreateCall(SanCovTracePCGuard, GuardPtr);
    IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge.
  } else {
    Value *GuardP = IRB.CreateAdd(
        IRB.CreatePointerCast(GuardArray, IntptrTy),
        ConstantInt::get(IntptrTy, (1 + NumberOfInstrumentedBlocks()) * 4));
    GuardP = IRB.CreateIntToPtr(GuardP, Int32PtrTy);
    if (Options.TraceBB) {
      IRB.CreateCall(IsEntryBB ? SanCovTraceEnter : SanCovTraceBB, GuardP);
    } else if (UseCalls) {
      IRB.CreateCall(SanCovWithCheckFunction, GuardP);
    } else {
      LoadInst *Load = IRB.CreateLoad(GuardP);
      Load->setAtomic(AtomicOrdering::Monotonic);
      Load->setAlignment(4);
      SetNoSanitizeMetadata(Load);
      Value *Cmp =
          IRB.CreateICmpSGE(Constant::getNullValue(Load->getType()), Load);
      Instruction *Ins = SplitBlockAndInsertIfThen(
          Cmp, &*IP, false, MDBuilder(*C).createBranchWeights(1, 100000));
      IRB.SetInsertPoint(Ins);
      IRB.SetCurrentDebugLocation(EntryLoc);
      // __sanitizer_cov gets the PC of the instruction using GET_CALLER_PC.
      IRB.CreateCall(SanCovFunction, GuardP);
      IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge.
    }
  }

  if (Options.Use8bitCounters) {
    IRB.SetInsertPoint(&*IP);
    Value *P = IRB.CreateAdd(
        IRB.CreatePointerCast(EightBitCounterArray, IntptrTy),
        ConstantInt::get(IntptrTy, NumberOfInstrumentedBlocks() - 1));
    P = IRB.CreateIntToPtr(P, IRB.getInt8PtrTy());
    LoadInst *LI = IRB.CreateLoad(P);
    Value *Inc = IRB.CreateAdd(LI, ConstantInt::get(IRB.getInt8Ty(), 1));
    StoreInst *SI = IRB.CreateStore(Inc, P);
    SetNoSanitizeMetadata(LI);
    SetNoSanitizeMetadata(SI);
  }
}

void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
                                                    bool UseCalls) {
  // Don't insert coverage for unreachable blocks: we will never call
  // __sanitizer_cov() for them, so counting them in
  // NumberOfInstrumentedBlocks() might complicate calculation of code coverage
  // percentage. Also, unreachable instructions frequently have no debug
  // locations.
  if (isa<UnreachableInst>(BB.getTerminator()))
    return;
  BasicBlock::iterator IP = BB.getFirstInsertionPt();

  bool IsEntryBB = &BB == &F.getEntryBlock();
  DebugLoc EntryLoc;
  if (IsEntryBB) {
    if (auto SP = getDISubprogram(&F))
      EntryLoc = DebugLoc::get(SP->getScopeLine(), 0, SP);
    // Keep static allocas and llvm.localescape calls in the entry block.  Even
    // if we aren't splitting the block, it's nice for allocas to be before
    // calls.
    IP = PrepareToSplitEntryBlock(BB, IP);
  } else {
    EntryLoc = IP->getDebugLoc();
  }

  IRBuilder<> IRB(&*IP);
  IRB.SetCurrentDebugLocation(EntryLoc);
  Value *GuardP = IRB.CreateAdd(
      IRB.CreatePointerCast(GuardArray, IntptrTy),
      ConstantInt::get(IntptrTy, (1 + NumberOfInstrumentedBlocks()) * 4));
  Type *Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty());
  GuardP = IRB.CreateIntToPtr(GuardP, Int32PtrTy);
  if (Options.TracePC) {
    IRB.CreateCall(SanCovTracePC);
  } else if (Options.TraceBB) {
    IRB.CreateCall(IsEntryBB ? SanCovTraceEnter : SanCovTraceBB, GuardP);
  } else if (UseCalls) {
    IRB.CreateCall(SanCovWithCheckFunction, GuardP);
  } else {
    LoadInst *Load = IRB.CreateLoad(GuardP);
    Load->setAtomic(Monotonic);
    Load->setAlignment(4);
    SetNoSanitizeMetadata(Load);
    Value *Cmp = IRB.CreateICmpSGE(Constant::getNullValue(Load->getType()), Load);
    Instruction *Ins = SplitBlockAndInsertIfThen(
        Cmp, &*IP, false, MDBuilder(*C).createBranchWeights(1, 100000));
    IRB.SetInsertPoint(Ins);
    IRB.SetCurrentDebugLocation(EntryLoc);
    // __sanitizer_cov gets the PC of the instruction using GET_CALLER_PC.
    IRB.CreateCall(SanCovFunction, GuardP);
    IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge.
  }

  if (Options.Use8bitCounters) {
    IRB.SetInsertPoint(&*IP);
    Value *P = IRB.CreateAdd(
        IRB.CreatePointerCast(EightBitCounterArray, IntptrTy),
        ConstantInt::get(IntptrTy, NumberOfInstrumentedBlocks() - 1));
    P = IRB.CreateIntToPtr(P, IRB.getInt8PtrTy());
    LoadInst *LI = IRB.CreateLoad(P);
    Value *Inc = IRB.CreateAdd(LI, ConstantInt::get(IRB.getInt8Ty(), 1));
    StoreInst *SI = IRB.CreateStore(Inc, P);
    SetNoSanitizeMetadata(LI);
    SetNoSanitizeMetadata(SI);
  }
}

void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
                                                    bool UseCalls) {
  // Don't insert coverage for unreachable blocks: we will never call
  // __sanitizer_cov() for them, so counting them in
  // NumberOfInstrumentedBlocks() might complicate calculation of code coverage
  // percentage. Also, unreachable instructions frequently have no debug
  // locations.
  if (isa<UnreachableInst>(BB.getTerminator()))
    return;
  BasicBlock::iterator IP = BB.getFirstInsertionPt(), BE = BB.end();
  // Skip static allocas at the top of the entry block so they don't become
  // dynamic when we split the block.  If we used our optimized stack layout,
  // then there will only be one alloca and it will come first.
  for (; IP != BE; ++IP) {
    AllocaInst *AI = dyn_cast<AllocaInst>(IP);
    if (!AI || !AI->isStaticAlloca())
      break;
  }

  bool IsEntryBB = &BB == &F.getEntryBlock();
  DebugLoc EntryLoc;
  if (IsEntryBB) {
    if (auto SP = getDISubprogram(&F))
      EntryLoc = DebugLoc::get(SP->getScopeLine(), 0, SP);
  } else {
    EntryLoc = IP->getDebugLoc();
  }

  IRBuilder<> IRB(IP);
  IRB.SetCurrentDebugLocation(EntryLoc);
  SmallVector<Value *, 1> Indices;
  Value *GuardP = IRB.CreateAdd(
      IRB.CreatePointerCast(GuardArray, IntptrTy),
      ConstantInt::get(IntptrTy, (1 + NumberOfInstrumentedBlocks()) * 4));
  Type *Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty());
  GuardP = IRB.CreateIntToPtr(GuardP, Int32PtrTy);
  if (UseCalls) {
    IRB.CreateCall(SanCovWithCheckFunction, GuardP);
  } else {
    LoadInst *Load = IRB.CreateLoad(GuardP);
    Load->setAtomic(Monotonic);
    Load->setAlignment(4);
    SetNoSanitizeMetadata(Load);
    Value *Cmp = IRB.CreateICmpSGE(Constant::getNullValue(Load->getType()), Load);
    Instruction *Ins = SplitBlockAndInsertIfThen(
        Cmp, IP, false, MDBuilder(*C).createBranchWeights(1, 100000));
    IRB.SetInsertPoint(Ins);
    IRB.SetCurrentDebugLocation(EntryLoc);
    // __sanitizer_cov gets the PC of the instruction using GET_CALLER_PC.
    IRB.CreateCall(SanCovFunction, GuardP);
    IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge.
  }

  if (Options.Use8bitCounters) {
    IRB.SetInsertPoint(IP);
    Value *P = IRB.CreateAdd(
        IRB.CreatePointerCast(EightBitCounterArray, IntptrTy),
        ConstantInt::get(IntptrTy, NumberOfInstrumentedBlocks() - 1));
    P = IRB.CreateIntToPtr(P, IRB.getInt8PtrTy());
    LoadInst *LI = IRB.CreateLoad(P);
    Value *Inc = IRB.CreateAdd(LI, ConstantInt::get(IRB.getInt8Ty(), 1));
    StoreInst *SI = IRB.CreateStore(Inc, P);
    SetNoSanitizeMetadata(LI);
    SetNoSanitizeMetadata(SI);
  }

  if (Options.TraceBB) {
    // Experimental support for tracing.
    // Insert a callback with the same guard variable as used for coverage.
    IRB.SetInsertPoint(IP);
    IRB.CreateCall(IsEntryBB ? SanCovTraceEnter : SanCovTraceBB, GuardP);
  }
}