C++ SILGenFunction::emitManagedRetain方法代码示例

/// Specialized emitter for Builtin.reinterpretCast.
static ManagedValue emitBuiltinReinterpretCast(SILGenFunction &gen,
                                         SILLocation loc,
                                         ArrayRef<Substitution> substitutions,
                                         ArrayRef<ManagedValue> args,
                                         CanFunctionType formalApplyType,
                                         SGFContext C) {
  assert(args.size() == 1 && "reinterpretCast should be given one argument");
  assert(substitutions.size() == 2 && "reinterpretCast should have two subs");
  
  auto &fromTL = gen.getTypeLowering(substitutions[0].getReplacement());
  auto &toTL = gen.getTypeLowering(substitutions[1].getReplacement());
  
  // If casting between address-only types, cast the address.
  if (!fromTL.isLoadable() || !toTL.isLoadable()) {
    SILValue fromAddr;

    // If the from value is loadable, move it to a buffer.
    if (fromTL.isLoadable()) {
      fromAddr = gen.emitTemporaryAllocation(loc, args[0].getValue()->getType());
      gen.B.createStore(loc, args[0].getValue(), fromAddr);
    } else {
      fromAddr = args[0].getValue();
    }
    auto toAddr = gen.B.createUncheckedAddrCast(loc, fromAddr,
                                      toTL.getLoweredType().getAddressType());
    
    // Load and retain the destination value if it's loadable. Leave the cleanup
    // on the original value since we don't know anything about it's type.
    if (toTL.isLoadable()) {
      SILValue val = gen.B.createLoad(loc, toAddr);
      return gen.emitManagedRetain(loc, val, toTL);
    }
    // Leave the cleanup on the original value.
    if (toTL.isTrivial())
      return ManagedValue::forUnmanaged(toAddr);

    // Initialize the +1 result buffer without taking the incoming value. The
    // source and destination cleanups will be independent.
    auto buffer = gen.getBufferForExprResult(loc, toTL.getLoweredType(), C);
    gen.B.createCopyAddr(loc, toAddr, buffer, IsNotTake, IsInitialization);
    return gen.manageBufferForExprResult(buffer, toTL, C);
  }
  // Create the appropriate bitcast based on the source and dest types.
  auto &in = args[0];
  SILValue out = gen.B.createUncheckedBitCast(loc, in.getValue(),
                                              toTL.getLoweredType());

  // If the cast reduces to unchecked_ref_cast, then the source and dest
  // have identical cleanup, so just forward the cleanup as an optimization.
  if (isa<UncheckedRefCastInst>(out))
    return ManagedValue(out, in.getCleanup());

  // Otherwise leave the original cleanup and retain the cast value.
  return gen.emitManagedRetain(loc, out, toTL);
}

/// Specialized emitter for Builtin.reinterpretCast.
static ManagedValue emitBuiltinReinterpretCast(SILGenFunction &SGF,
                                         SILLocation loc,
                                         SubstitutionMap substitutions,
                                         ArrayRef<ManagedValue> args,
                                         SGFContext C) {
  assert(args.size() == 1 && "reinterpretCast should be given one argument");
  assert(substitutions.getReplacementTypes().size() == 2 &&
         "reinterpretCast should have two subs");
  
  auto &fromTL = SGF.getTypeLowering(substitutions.getReplacementTypes()[0]);
  auto &toTL = SGF.getTypeLowering(substitutions.getReplacementTypes()[1]);
  
  // If casting between address types, cast the address.
  if (fromTL.isAddress() || toTL.isAddress()) {
    SILValue fromAddr;

    // If the from value is not an address, move it to a buffer.
    if (!fromTL.isAddress()) {
      fromAddr = SGF.emitTemporaryAllocation(loc, args[0].getValue()->getType());
      fromTL.emitStore(SGF.B, loc, args[0].getValue(), fromAddr,
                       StoreOwnershipQualifier::Init);
    } else {
      fromAddr = args[0].getValue();
    }
    auto toAddr = SGF.B.createUncheckedAddrCast(loc, fromAddr,
                                      toTL.getLoweredType().getAddressType());
    
    // Load and retain the destination value if it's loadable. Leave the cleanup
    // on the original value since we don't know anything about it's type.
    if (!toTL.isAddress()) {
      return SGF.emitManagedLoadCopy(loc, toAddr, toTL);
    }
    // Leave the cleanup on the original value.
    if (toTL.isTrivial())
      return ManagedValue::forUnmanaged(toAddr);

    // Initialize the +1 result buffer without taking the incoming value. The
    // source and destination cleanups will be independent.
    return SGF.B.bufferForExpr(
        loc, toTL.getLoweredType(), toTL, C,
        [&](SILValue bufferAddr) {
          SGF.B.createCopyAddr(loc, toAddr, bufferAddr, IsNotTake,
                               IsInitialization);
        });
  }
  // Create the appropriate bitcast based on the source and dest types.
  ManagedValue in = args[0];
  SILType resultTy = toTL.getLoweredType();
  if (resultTy.isTrivial(SGF.F))
    return SGF.B.createUncheckedTrivialBitCast(loc, in, resultTy);

  // If we can perform a ref cast, just return.
  if (auto refCast = SGF.B.tryCreateUncheckedRefCast(loc, in, resultTy))
    return refCast;

  // Otherwise leave the original cleanup and retain the cast value.
  SILValue out = SGF.B.createUncheckedBitwiseCast(loc, in.getValue(), resultTy);
  return SGF.emitManagedRetain(loc, out, toTL);
}

static ManagedValue emitBuiltinValueToBridgeObject(SILGenFunction &SGF,
                                                   SILLocation loc,
                                                   SubstitutionMap subs,
                                                   ArrayRef<ManagedValue> args,
                                                   SGFContext C) {
  assert(args.size() == 1 && "ValueToBridgeObject should have one argument");
  assert(subs.getReplacementTypes().size() == 1 &&
         "ValueToBridgeObject should have one sub");

  Type argTy = subs.getReplacementTypes()[0];
  if (!argTy->is<BuiltinIntegerType>()) {
    SGF.SGM.diagnose(loc, diag::invalid_sil_builtin,
                     "argument to builtin should be a builtin integer");
    SILType objPointerType = SILType::getBridgeObjectType(SGF.F.getASTContext());
    return SGF.emitUndef(objPointerType);
  }

  SILValue result = SGF.B.createValueToBridgeObject(loc, args[0].getValue());
  return SGF.emitManagedRetain(loc, result);
}

/// Specialized emitter for Builtin.bridgeFromRawPointer.
static ManagedValue emitBuiltinBridgeFromRawPointer(SILGenFunction &SGF,
                                        SILLocation loc,
                                        SubstitutionList substitutions,
                                        ArrayRef<ManagedValue> args,
                                        SGFContext C) {
  assert(substitutions.size() == 1 &&
         "bridge should have a single substitution");
  assert(args.size() == 1 && "bridge should have a single argument");
  
  // The substitution determines the destination type.
  // FIXME: Archetype destination type?
  auto &destLowering = SGF.getTypeLowering(substitutions[0].getReplacement());
  assert(destLowering.isLoadable());
  SILType destType = destLowering.getLoweredType();

  // Take the raw pointer argument and cast it to the destination type.
  SILValue result = SGF.B.createRawPointerToRef(loc, args[0].getUnmanagedValue(),
                                                destType);
  // The result has ownership semantics, so retain it with a cleanup.
  return SGF.emitManagedRetain(loc, result, destLowering);
}

static void buildFuncToBlockInvokeBody(SILGenFunction &gen,
                                       SILLocation loc,
                                       CanSILFunctionType blockTy,
                                       CanSILBlockStorageType blockStorageTy,
                                       CanSILFunctionType funcTy) {
  Scope scope(gen.Cleanups, CleanupLocation::get(loc));
  SILBasicBlock *entry = &*gen.F.begin();

  // Get the captured native function value out of the block.
  auto storageAddrTy = SILType::getPrimitiveAddressType(blockStorageTy);
  auto storage = new (gen.SGM.M) SILArgument(entry, storageAddrTy);
  auto capture = gen.B.createProjectBlockStorage(loc, storage);
  auto &funcTL = gen.getTypeLowering(funcTy);
  auto fn = gen.emitLoad(loc, capture, funcTL, SGFContext(), IsNotTake);

  // Collect the block arguments, which may have nonstandard conventions.
  assert(blockTy->getParameters().size()
         == funcTy->getParameters().size()
         && "block and function types don't match");

  SmallVector<ManagedValue, 4> args;
  for (unsigned i : indices(funcTy->getParameters())) {
    auto &funcParam = funcTy->getParameters()[i];
    auto &param = blockTy->getParameters()[i];
    SILValue v = new (gen.SGM.M) SILArgument(entry, param.getSILType());

    ManagedValue mv;
    
    // If the parameter is a block, we need to copy it to ensure it lives on
    // the heap. The adapted closure value might outlive the block's original
    // scope.
    if (param.getSILType().isBlockPointerCompatible()) {
      // We still need to consume the original block if it was owned.
      switch (param.getConvention()) {
      case ParameterConvention::Direct_Owned:
        gen.emitManagedRValueWithCleanup(v);
        break;
        
      case ParameterConvention::Direct_Deallocating:
      case ParameterConvention::Direct_Guaranteed:
      case ParameterConvention::Direct_Unowned:
        break;
        
      case ParameterConvention::Indirect_In:
      case ParameterConvention::Indirect_In_Guaranteed:
      case ParameterConvention::Indirect_Inout:
      case ParameterConvention::Indirect_InoutAliasable:
        llvm_unreachable("indirect params to blocks not supported");
      }
      
      SILValue blockCopy = gen.B.createCopyBlock(loc, v);
      mv = gen.emitManagedRValueWithCleanup(blockCopy);
    } else {
      switch (param.getConvention()) {
      case ParameterConvention::Direct_Owned:
        // Consume owned parameters at +1.
        mv = gen.emitManagedRValueWithCleanup(v);
        break;

      case ParameterConvention::Direct_Guaranteed:
      case ParameterConvention::Direct_Unowned:
        // We need to independently retain the value.
        mv = gen.emitManagedRetain(loc, v);
        break;

      case ParameterConvention::Direct_Deallocating:
        // We do not need to retain the value since the value is already being
        // deallocated.
        mv = ManagedValue::forUnmanaged(v);
        break;

      case ParameterConvention::Indirect_In_Guaranteed:
      case ParameterConvention::Indirect_In:
      case ParameterConvention::Indirect_Inout:
      case ParameterConvention::Indirect_InoutAliasable:
        llvm_unreachable("indirect arguments to blocks not supported");
      }
    }
    
    args.push_back(gen.emitBridgedToNativeValue(loc, mv,
                                SILFunctionTypeRepresentation::CFunctionPointer,
                                funcParam.getType()));
  }

  // Call the native function.
  assert(!funcTy->hasIndirectResults()
         && "block thunking func with indirect result not supported");
  assert(funcTy->getNumDirectResults() <= 1
         && "block thunking func with multiple results not supported");
  ManagedValue result = gen.emitMonomorphicApply(loc, fn, args,
                         funcTy->getSILResult().getSwiftRValueType(),
                                                 ApplyOptions::None,
                                                 None, None)
    .getAsSingleValue(gen, loc);

  // Bridge the result back to ObjC.
  result = gen.emitNativeToBridgedValue(loc, result,
                        SILFunctionTypeRepresentation::CFunctionPointer,
                        blockTy->getSILResult().getSwiftRValueType());

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