C++ const_arg_iterator::getArgNo方法代码示例

// Clone OldFunc into NewFunc, transforming the old arguments into references to
// VMap values.
//
void llvm::CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
                             ValueToValueMapTy &VMap,
                             bool ModuleLevelChanges,
                             SmallVectorImpl<ReturnInst*> &Returns,
                             const char *NameSuffix, ClonedCodeInfo *CodeInfo) {
  assert(NameSuffix && "NameSuffix cannot be null!");

#ifndef NDEBUG
  for (Function::const_arg_iterator I = OldFunc->arg_begin(), 
       E = OldFunc->arg_end(); I != E; ++I)
    assert(VMap.count(I) && "No mapping from source argument specified!");
#endif

  // Clone any attributes.
  if (NewFunc->arg_size() == OldFunc->arg_size())
    NewFunc->copyAttributesFrom(OldFunc);
  else {
    //Some arguments were deleted with the VMap. Copy arguments one by one
    for (Function::const_arg_iterator I = OldFunc->arg_begin(), 
           E = OldFunc->arg_end(); I != E; ++I)
      if (Argument* Anew = dyn_cast<Argument>(VMap[I]))
        Anew->addAttr( OldFunc->getAttributes()
                       .getParamAttributes(I->getArgNo() + 1));
    NewFunc->setAttributes(NewFunc->getAttributes()
                           .addAttr(0, OldFunc->getAttributes()
                                     .getRetAttributes()));
    NewFunc->setAttributes(NewFunc->getAttributes()
                           .addAttr(~0, OldFunc->getAttributes()
                                     .getFnAttributes()));

  }

  // Loop over all of the basic blocks in the function, cloning them as
  // appropriate.  Note that we save BE this way in order to handle cloning of
  // recursive functions into themselves.
  //
  for (Function::const_iterator BI = OldFunc->begin(), BE = OldFunc->end();
       BI != BE; ++BI) {
    const BasicBlock &BB = *BI;

    // Create a new basic block and copy instructions into it!
    BasicBlock *CBB = CloneBasicBlock(&BB, VMap, NameSuffix, NewFunc, CodeInfo);
    VMap[&BB] = CBB;                       // Add basic block mapping.

    if (ReturnInst *RI = dyn_cast<ReturnInst>(CBB->getTerminator()))
      Returns.push_back(RI);
  }

  // Loop over all of the instructions in the function, fixing up operand
  // references as we go.  This uses VMap to do all the hard work.
  for (Function::iterator BB = cast<BasicBlock>(VMap[OldFunc->begin()]),
         BE = NewFunc->end(); BB != BE; ++BB)
    // Loop over all instructions, fixing each one as we find it...
    for (BasicBlock::iterator II = BB->begin(); II != BB->end(); ++II)
      RemapInstruction(II, VMap,
                       ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);
}

static bool ffiInvoke(RawFunc Fn, Function *F, ArrayRef<GenericValue> ArgVals,
                      const DataLayout &TD, GenericValue &Result) {
  ffi_cif cif;
  FunctionType *FTy = F->getFunctionType();
  const unsigned NumArgs = F->arg_size();

  // TODO: We don't have type information about the remaining arguments, because
  // this information is never passed into ExecutionEngine::runFunction().
  if (ArgVals.size() > NumArgs && F->isVarArg()) {
    report_fatal_error("Calling external var arg function '" + F->getName()
                      + "' is not supported by the Interpreter.");
  }

  unsigned ArgBytes = 0;

  std::vector<ffi_type*> args(NumArgs);
  for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end();
       A != E; ++A) {
    const unsigned ArgNo = A->getArgNo();
    Type *ArgTy = FTy->getParamType(ArgNo);
    args[ArgNo] = ffiTypeFor(ArgTy);
    ArgBytes += TD.getTypeStoreSize(ArgTy);
  }

  SmallVector<uint8_t, 128> ArgData;
  ArgData.resize(ArgBytes);
  uint8_t *ArgDataPtr = ArgData.data();
  SmallVector<void*, 16> values(NumArgs);
  for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end();
       A != E; ++A) {
    const unsigned ArgNo = A->getArgNo();
    Type *ArgTy = FTy->getParamType(ArgNo);
    values[ArgNo] = ffiValueFor(ArgTy, ArgVals[ArgNo], ArgDataPtr);
    ArgDataPtr += TD.getTypeStoreSize(ArgTy);
  }

  Type *RetTy = FTy->getReturnType();
  ffi_type *rtype = ffiTypeFor(RetTy);

  if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, NumArgs, rtype, args.data()) ==
      FFI_OK) {
    SmallVector<uint8_t, 128> ret;
    if (RetTy->getTypeID() != Type::VoidTyID)
      ret.resize(TD.getTypeStoreSize(RetTy));
    ffi_call(&cif, Fn, ret.data(), values.data());
    switch (RetTy->getTypeID()) {
      case Type::IntegerTyID:
        switch (cast<IntegerType>(RetTy)->getBitWidth()) {
          case 8:  Result.IntVal = APInt(8 , *(int8_t *) ret.data()); break;
          case 16: Result.IntVal = APInt(16, *(int16_t*) ret.data()); break;
          case 32: Result.IntVal = APInt(32, *(int32_t*) ret.data()); break;
          case 64: Result.IntVal = APInt(64, *(int64_t*) ret.data()); break;
        }
        break;
      case Type::FloatTyID:   Result.FloatVal   = *(float *) ret.data(); break;
      case Type::DoubleTyID:  Result.DoubleVal  = *(double*) ret.data(); break;
      case Type::PointerTyID: Result.PointerVal = *(void **) ret.data(); break;
      default: break;
    }
    return true;
  }

  return false;
}

// Clone OldFunc into NewFunc, transforming the old arguments into references to
// VMap values.
//
void llvm::CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
                             ValueToValueMapTy &VMap,
                             bool ModuleLevelChanges,
                             SmallVectorImpl<ReturnInst*> &Returns,
                             const char *NameSuffix, ClonedCodeInfo *CodeInfo,
                             ValueMapTypeRemapper *TypeMapper) {
  assert(NameSuffix && "NameSuffix cannot be null!");

#ifndef NDEBUG
  for (Function::const_arg_iterator I = OldFunc->arg_begin(), 
       E = OldFunc->arg_end(); I != E; ++I)
    assert(VMap.count(I) && "No mapping from source argument specified!");
#endif

  // Clone any attributes.
  if (NewFunc->arg_size() == OldFunc->arg_size())
    NewFunc->copyAttributesFrom(OldFunc);
  else {
    //Some arguments were deleted with the VMap. Copy arguments one by one
    for (Function::const_arg_iterator I = OldFunc->arg_begin(), 
           E = OldFunc->arg_end(); I != E; ++I)
      if (Argument* Anew = dyn_cast<Argument>(VMap[I]))
        Anew->addAttr( OldFunc->getAttributes()
                       .getParamAttributes(I->getArgNo() + 1));
    NewFunc->setAttributes(NewFunc->getAttributes()
                           .addAttr(0, OldFunc->getAttributes()
                                     .getRetAttributes()));
    NewFunc->setAttributes(NewFunc->getAttributes()
                           .addAttr(~0, OldFunc->getAttributes()
                                     .getFnAttributes()));

  }

  // Loop over all of the basic blocks in the function, cloning them as
  // appropriate.  Note that we save BE this way in order to handle cloning of
  // recursive functions into themselves.
  //
  for (Function::const_iterator BI = OldFunc->begin(), BE = OldFunc->end();
       BI != BE; ++BI) {
    const BasicBlock &BB = *BI;

    // Create a new basic block and copy instructions into it!
    BasicBlock *CBB = CloneBasicBlock(&BB, VMap, NameSuffix, NewFunc, CodeInfo);

    // Add basic block mapping.
    VMap[&BB] = CBB;

    // It is only legal to clone a function if a block address within that
    // function is never referenced outside of the function.  Given that, we
    // want to map block addresses from the old function to block addresses in
    // the clone. (This is different from the generic ValueMapper
    // implementation, which generates an invalid blockaddress when
    // cloning a function.)
    if (BB.hasAddressTaken()) {
      Constant *OldBBAddr = BlockAddress::get(const_cast<Function*>(OldFunc),
                                              const_cast<BasicBlock*>(&BB));
      VMap[OldBBAddr] = BlockAddress::get(NewFunc, CBB);                                         
    }

    // Note return instructions for the caller.
    if (ReturnInst *RI = dyn_cast<ReturnInst>(CBB->getTerminator()))
      Returns.push_back(RI);
  }

  // Loop over all of the instructions in the function, fixing up operand
  // references as we go.  This uses VMap to do all the hard work.
  for (Function::iterator BB = cast<BasicBlock>(VMap[OldFunc->begin()]),
         BE = NewFunc->end(); BB != BE; ++BB)
    // Loop over all instructions, fixing each one as we find it...
    for (BasicBlock::iterator II = BB->begin(); II != BB->end(); ++II)
      RemapInstruction(II, VMap,
                       ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges,
                       TypeMapper);
}