Esempio n. 1
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/// Given an aggregate value and an access path, extract the value indicated by
/// the path.
static SILValue ExtractSubElement(SILValue Val, unsigned SubElementNumber,
                                  SILBuilder &B, SILLocation Loc) {
  SILType ValTy = Val->getType();
  
  // Extract tuple elements.
  if (auto TT = ValTy.getAs<TupleType>()) {
    for (unsigned EltNo : indices(TT.getElementTypes())) {
      // Keep track of what subelement is being referenced.
      SILType EltTy = ValTy.getTupleElementType(EltNo);
      unsigned NumSubElt = getNumSubElements(EltTy, B.getModule());
      if (SubElementNumber < NumSubElt) {
        Val = B.emitTupleExtract(Loc, Val, EltNo, EltTy);
        return ExtractSubElement(Val, SubElementNumber, B, Loc);
      }
      
      SubElementNumber -= NumSubElt;
    }
    
    llvm_unreachable("Didn't find field");
  }
  
  // Extract struct elements.
  if (auto *SD = getFullyReferenceableStruct(ValTy)) {
    for (auto *D : SD->getStoredProperties()) {
      auto fieldType = ValTy.getFieldType(D, B.getModule());
      unsigned NumSubElt = getNumSubElements(fieldType, B.getModule());
      
      if (SubElementNumber < NumSubElt) {
        Val = B.emitStructExtract(Loc, Val, D);
        return ExtractSubElement(Val, SubElementNumber, B, Loc);
      }
      
      SubElementNumber -= NumSubElt;
      
    }
    llvm_unreachable("Didn't find field");
  }
  
  // Otherwise, we're down to a scalar.
  assert(SubElementNumber == 0 && "Miscalculation indexing subelements");
  return Val;
}
Esempio n. 2
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// Simplify:
//   %1 = unchecked_enum_data %0 : $Optional<C>, #Optional.Some!enumelt.1
//   %2 = enum $Optional<C>, #Optional.Some!enumelt.1, %1 : $C
// to %0 since we are building the same enum.
static SILValue simplifyEnumFromUncheckedEnumData(EnumInst *EI) {
  assert(EI->hasOperand() && "Expected an enum with an operand!");

  auto *UEDI = dyn_cast<UncheckedEnumDataInst>(EI->getOperand());
  if (!UEDI || UEDI->getElement() != EI->getElement())
    return SILValue();
  
  SILValue EnumOp = UEDI->getOperand();
  
  // Same enum elements don't necessarily imply same enum types.
  // Enum types may be different if the enum is generic, e.g.
  // E<Int>.Case and E<Double>.Case.
  SILType OriginalEnum = EnumOp->getType();
  SILType NewEnum = EI->getType();

  if (OriginalEnum != NewEnum)
    return SILValue();
  
  return EnumOp;
}
Esempio n. 3
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/// Check if we can pass/convert all arguments of the original apply
/// as required by the found devirtualized method.
static bool
canPassOrConvertAllArguments(ApplySite AI,
                             CanSILFunctionType SubstCalleeCanType) {
  for (unsigned ArgN = 0, ArgE = AI.getNumArguments(); ArgN != ArgE; ++ArgN) {
    SILValue A = AI.getArgument(ArgN);
    auto ParamType = SubstCalleeCanType->getSILArgumentType(
      SubstCalleeCanType->getNumSILArguments() - AI.getNumArguments() + ArgN);
    // Check if we can cast the provided argument into the required
    // parameter type.
    auto FromTy = A->getType();
    auto ToTy = ParamType;
    // If types are the same, no conversion will be required.
    if (FromTy == ToTy)
      continue;
    // Otherwise, it should be possible to upcast the arguments.
    if (!isLegalUpcast(FromTy, ToTy))
      return false;
  }
  return true;
}
Esempio n. 4
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SILValue swift::stripUpCasts(SILValue v) {
  assert(v->getType().isClassOrClassMetatype() &&
         "Expected class or class metatype!");
  
  v = stripSinglePredecessorArgs(v);
  
  while (true) {
    if (auto *ui = dyn_cast<UpcastInst>(v)) {
      v = ui->getOperand();
      continue;
    }

    SILValue v2 = stripSinglePredecessorArgs(v);
    v2 = stripOwnershipInsts(v2);
    if (v2 == v) {
      return v2;
    }
    v = v2;
  }
}
Esempio n. 5
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NullablePtr<SILInstruction>
Projection::
createAddrProjection(SILBuilder &B, SILLocation Loc, SILValue Base) const {
    // Grab Base's type.
    SILType BaseTy = Base.getType();

    // If BaseTy is not an address type, bail.
    if (!BaseTy.isAddress())
        return nullptr;

    // If this projection is associated with an object type, convert its type to
    // an address type.
    //
    // *NOTE* We purposely do not handle local storage types here since we want to
    // always fail in such a case. That is handled by checking that Ty is an
    // address.
    SILType Ty = Type.isObject()? Type.getAddressType() : Type;

    if (!Ty.isAddress())
        return nullptr;

    // Ok, we now know that the type of Base and the type represented by the base
    // of this projection match and that this projection can be represented as
    // value. Create the instruction if we can. Otherwise, return nullptr.
    switch (getKind()) {
    case ProjectionKind::Struct:
        return B.createStructElementAddr(Loc, Base, cast<VarDecl>(getDecl()));
    case ProjectionKind::Tuple:
        return B.createTupleElementAddr(Loc, Base, getIndex());
    case ProjectionKind::Index: {
        auto Ty = SILType::getBuiltinIntegerType(32, B.getASTContext());
        auto *IntLiteral = B.createIntegerLiteral(Loc, Ty, getIndex());
        return B.createIndexAddr(Loc, Base, IntLiteral);
    }
    case ProjectionKind::Enum:
        return B.createUncheckedTakeEnumDataAddr(Loc, Base,
                cast<EnumElementDecl>(getDecl()));
    case ProjectionKind::Class:
        return B.createRefElementAddr(Loc, Base, cast<VarDecl>(getDecl()));
    }
}
Esempio n. 6
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static void assignRecursive(SILGenFunction &gen, SILLocation loc,
                            CanType type, ArrayRef<ManagedValue> &srcValues,
                            SILValue destAddr) {
  // Recurse into tuples.
  if (auto srcTupleType = dyn_cast<TupleType>(type)) {
    assert(destAddr->getType().castTo<TupleType>()->getNumElements()
             == srcTupleType->getNumElements());
    for (auto eltIndex : indices(srcTupleType.getElementTypes())) {
      auto eltDestAddr = gen.B.createTupleElementAddr(loc, destAddr, eltIndex);
      assignRecursive(gen, loc, srcTupleType.getElementType(eltIndex),
                      srcValues, eltDestAddr);
    }
    return;
  }

  // Otherwise, pull the front value off the list.
  auto srcValue = srcValues.front();
  srcValues = srcValues.slice(1);

  srcValue.assignInto(gen, loc, destAddr);
}
Esempio n. 7
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static ManagedValue emitBridgeNSStringToString(SILGenFunction &gen,
                                               SILLocation loc,
                                               ManagedValue nsstr) {
  SILValue bridgeFn =
      gen.emitGlobalFunctionRef(loc, gen.SGM.getNSStringToStringFn());

  Type inputType = nsstr.getType().getSwiftRValueType();
  if (!inputType->getOptionalObjectType()) {
    SILType loweredOptTy = gen.SGM.getLoweredType(OptionalType::get(inputType));
    auto *someDecl = gen.getASTContext().getOptionalSomeDecl();
    auto *enumInst = gen.B.createEnum(loc, nsstr.getValue(), someDecl,
                                      loweredOptTy);
    nsstr = ManagedValue(enumInst, nsstr.getCleanup());
  }

  SILType nativeTy = gen.getLoweredType(gen.SGM.Types.getStringType());
  SILValue str = gen.B.createApply(loc, bridgeFn, bridgeFn.getType(), nativeTy,
                                   {}, { nsstr.forward(gen) });

  return gen.emitManagedRValueWithCleanup(str);
}
static bool expandReleaseValue(ReleaseValueInst *DV) {
  SILModule &Module = DV->getModule();
  SILBuilderWithScope Builder(DV);

  // Strength reduce destroy_addr inst into release/store if
  // we have a non-address only type.
  SILValue Value = DV->getOperand();

  // If we have an address only type, do nothing.
  SILType Type = Value->getType();
  assert(Type.isLoadable(Module) &&
         "release_value should never be called on a non-loadable type.");

  auto &TL = Module.getTypeLowering(Type);
  TL.emitLoweredDestroyValue(Builder, DV->getLoc(), Value,
                             TypeLowering::LoweringStyle::Deep);

  DEBUG(llvm::dbgs() << "    Expanding Destroy Value: " << *DV);

  ++NumExpand;
  return true;
}
/// Use the summary analysis to check whether a call to the given
/// function would conflict with any in progress accesses. The starting
/// index indicates what index into the the callee's parameters the
/// arguments array starts at -- this is useful for partial_apply functions,
/// which pass only a suffix of the callee's arguments at the apply site.
static void checkForViolationWithCall(
    const StorageMap &Accesses, SILFunction *Callee, unsigned StartingAtIndex,
    OperandValueArrayRef Arguments, AccessSummaryAnalysis *ASA,
    llvm::SmallVectorImpl<ConflictingAccess> &ConflictingAccesses) {
  const AccessSummaryAnalysis::FunctionSummary &FS =
      ASA->getOrCreateSummary(Callee);

  // For each argument in the suffix of the callee arguments being passed
  // at this call site, determine whether the arguments will be accessed
  // in a way that conflicts with any currently in progress accesses.
  // If so, diagnose.
  for (unsigned ArgumentIndex : indices(Arguments)) {
    unsigned CalleeIndex = StartingAtIndex + ArgumentIndex;

    const AccessSummaryAnalysis::ArgumentSummary &AS =
        FS.getAccessForArgument(CalleeIndex);

    const auto &SubAccesses = AS.getSubAccesses();

    // Is the capture accessed in the callee?
    if (SubAccesses.size() == 0)
      continue;

    SILValue Argument = Arguments[ArgumentIndex];
    assert(Argument->getType().isAddress());

    const AccessedStorage &Storage = findAccessedStorage(Argument);
    auto AccessIt = Accesses.find(Storage);

    // Are there any accesses in progress at the time of the call?
    if (AccessIt == Accesses.end())
      continue;

    const AccessInfo &Info = AccessIt->getSecond();
    if (auto Conflict = findConflictingArgumentAccess(AS, Storage, Info)) {
      ConflictingAccesses.push_back(*Conflict);
    }
  }
}
Esempio n. 10
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void SILGenFunction::emitInjectOptionalValueInto(SILLocation loc,
                                                 ArgumentSource &&value,
                                                 SILValue dest,
                                                 const TypeLowering &optTL) {
  SILType optType = optTL.getLoweredType();
  assert(dest->getType() == optType.getAddressType());
  auto loweredPayloadTy = optType.getAnyOptionalObjectType();
  assert(loweredPayloadTy);

  // Project out the payload area.
  auto someDecl = getASTContext().getOptionalSomeDecl();
  auto destPayload =
    B.createInitEnumDataAddr(loc, dest, someDecl,
                             loweredPayloadTy.getAddressType());
  
  // Emit the value into the payload area.
  TemporaryInitialization emitInto(destPayload, CleanupHandle::invalid());
  std::move(value).forwardInto(*this, &emitInto);
  
  // Inject the tag.
  B.createInjectEnumAddr(loc, dest, someDecl);
}
Esempio n. 11
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SILInstruction *SILCombiner::visitSwitchValueInst(SwitchValueInst *SVI) {
  SILValue Cond = SVI->getOperand();
  BuiltinIntegerType *CondTy = Cond->getType().getAs<BuiltinIntegerType>();
  if (!CondTy || !CondTy->isFixedWidth(1))
    return nullptr;

  SILBasicBlock *FalseBB = nullptr;
  SILBasicBlock *TrueBB = nullptr;
  for (unsigned Idx = 0, Num = SVI->getNumCases(); Idx < Num; ++Idx) {
    auto Case = SVI->getCase(Idx);
    auto *CaseVal = dyn_cast<IntegerLiteralInst>(Case.first);
    if (!CaseVal)
      return nullptr;
    SILBasicBlock *DestBB = Case.second;
    assert(DestBB->args_empty() &&
           "switch_value case destination cannot take arguments");
    if (CaseVal->getValue() == 0) {
      assert(!FalseBB && "double case value 0 in switch_value");
      FalseBB = DestBB;
    } else {
      assert(!TrueBB && "double case value 1 in switch_value");
      TrueBB = DestBB;
    }
  }
  if (SVI->hasDefault()) {
    assert(SVI->getDefaultBB()->args_empty() &&
           "switch_value default destination cannot take arguments");
    if (!FalseBB) {
      FalseBB = SVI->getDefaultBB();
    } else if (!TrueBB) {
      TrueBB = SVI->getDefaultBB();
    }
  }
  if (!FalseBB || !TrueBB)
    return nullptr;

  Builder.setCurrentDebugScope(SVI->getDebugScope());
  return Builder.createCondBranch(SVI->getLoc(), Cond, TrueBB, FalseBB);
}
/// For each argument in the range of the callee arguments being applied at the
/// given apply site, use the summary analysis to determine whether the
/// arguments will be accessed in a way that conflicts with any currently in
/// progress accesses. If so, diagnose.
static void checkCaptureAccess(ApplySite Apply, AccessState &State) {
  SILFunction *Callee = Apply.getCalleeFunction();
  if (!Callee || Callee->empty())
    return;

  const AccessSummaryAnalysis::FunctionSummary &FS =
      State.ASA->getOrCreateSummary(Callee);

  for (unsigned ArgumentIndex : range(Apply.getNumArguments())) {

    unsigned CalleeIndex =
        Apply.getCalleeArgIndexOfFirstAppliedArg() + ArgumentIndex;

    const AccessSummaryAnalysis::ArgumentSummary &AS =
        FS.getAccessForArgument(CalleeIndex);

    const auto &SubAccesses = AS.getSubAccesses();

    // Is the capture accessed in the callee?
    if (SubAccesses.empty())
      continue;

    SILValue Argument = Apply.getArgument(ArgumentIndex);
    assert(Argument->getType().isAddress());

    // A valid AccessedStorage should alway sbe found because Unsafe accesses
    // are not tracked by AccessSummaryAnalysis.
    const AccessedStorage &Storage = findValidAccessedStorage(Argument);
    auto AccessIt = State.Accesses->find(Storage);

    // Are there any accesses in progress at the time of the call?
    if (AccessIt == State.Accesses->end())
      continue;

    const AccessInfo &Info = AccessIt->getSecond();
    if (auto Conflict = findConflictingArgumentAccess(AS, Storage, Info))
      State.ConflictingAccesses.push_back(*Conflict);
  }
}
Esempio n. 13
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static bool expandRetainValue(RetainValueInst *CV) {
  SILModule &Module = CV->getModule();
  SILBuilderWithScope Builder(CV);

  // Strength reduce destroy_addr inst into release/store if
  // we have a non-address only type.
  SILValue Value = CV->getOperand();

  // If we have an address only type, do nothing.
  SILType Type = Value->getType();
  assert(Type.isLoadable(Module) && "Copy Value can only be called on loadable "
         "types.");

  auto &TL = Module.getTypeLowering(Type);
  TL.emitLoweredCopyValue(Builder, CV->getLoc(), Value,
                          TypeLowering::LoweringStyle::DeepNoEnum);

  DEBUG(llvm::dbgs() << "    Expanding Copy Value: " << *CV);

  ++NumExpand;
  return true;
}
Esempio n. 14
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void CallSiteDescriptor::extendArgumentLifetime(
    SILValue Arg, SILArgumentConvention ArgConvention) const {
  assert(!CInfo->LifetimeFrontier.empty() &&
         "Need a post-dominating release(s)");

  auto ArgTy = Arg->getType();

  // Extend the lifetime of a captured argument to cover the callee.
  SILBuilderWithScope Builder(getClosure());

  // Indirect non-inout arguments are not supported yet.
  assert(!isNonInoutIndirectSILArgument(Arg, ArgConvention));

  if (ArgTy.isObject()) {
    Builder.createRetainValue(getClosure()->getLoc(), Arg,
                              Builder.getDefaultAtomicity());
    for (auto *I : CInfo->LifetimeFrontier) {
      Builder.setInsertionPoint(I);
      Builder.createReleaseValue(getClosure()->getLoc(), Arg,
                                 Builder.getDefaultAtomicity());
    }
  }
}
/// Helper function for simplifying conversions between
/// thick and objc metatypes.
static SILInstruction *
visitMetatypeConversionInst(SILBuilder &Builder, ConversionInst *MCI,
                            MetatypeRepresentation Representation) {
  SILValue Op = MCI->getOperand(0);
  // Instruction has a proper target type already.
  SILType Ty = MCI->getType();
  auto MetatypeTy = Op.getType().getAs<AnyMetatypeType>();

  if (MetatypeTy->getRepresentation() != Representation)
    return nullptr;

  if (isa<MetatypeInst>(Op))
    return Builder.createMetatype(MCI->getLoc(), Ty);

  if (auto *VMI = dyn_cast<ValueMetatypeInst>(Op))
    return Builder.createValueMetatype(MCI->getLoc(), Ty, VMI->getOperand());

  if (auto *EMI = dyn_cast<ExistentialMetatypeInst>(Op))
    return Builder.createExistentialMetatype(MCI->getLoc(), Ty,
                                             EMI->getOperand());

  return nullptr;
}
static void splitDestructure(SILBuilder &B, SILInstruction *I, SILValue Op) {
  assert((isa<DestructureStructInst>(I) || isa<DestructureTupleInst>(I)) &&
         "Only destructure operations can be passed to splitDestructure");

  SILModule &M = I->getModule();
  SILLocation Loc = I->getLoc();
  SILType OpType = Op->getType();

  llvm::SmallVector<Projection, 8> Projections;
  Projection::getFirstLevelProjections(OpType, M, Projections);
  assert(Projections.size() == I->getNumResults());

  llvm::SmallVector<SILValue, 8> NewValues;
  for (unsigned i : indices(Projections)) {
    const auto &Proj = Projections[i];
    NewValues.push_back(Proj.createObjectProjection(B, Loc, Op).get());
    assert(NewValues.back()->getType() == I->getResults()[i]->getType() &&
           "Expected created projections and results to be the same types");
  }

  I->replaceAllUsesPairwiseWith(NewValues);
  I->eraseFromParent();
}
Esempio n. 17
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NullablePtr<SILInstruction>
Projection::
createValueProjection(SILBuilder &B, SILLocation Loc, SILValue Base) const {
    // Grab Base's type.
    SILType BaseTy = Base.getType();

    // If BaseTy is not an object type, bail.
    if (!BaseTy.isObject())
        return nullptr;

    // If this projection is associated with an address type, convert its type to
    // an object type.
    //
    // We explicitly do not convert Type to be an object if it is a local storage
    // type since we want it to fail.
    SILType Ty = Type.isAddress()? Type.getObjectType() : Type;

    if (!Ty.isObject())
        return nullptr;

    // Ok, we now know that the type of Base and the type represented by the base
    // of this projection match and that this projection can be represented as
    // value. Create the instruction if we can. Otherwise, return nullptr.
    switch (getKind()) {
    case ProjectionKind::Struct:
        return B.createStructExtract(Loc, Base, cast<VarDecl>(getDecl()));
    case ProjectionKind::Tuple:
        return B.createTupleExtract(Loc, Base, getIndex());
    case ProjectionKind::Index:
        return nullptr;
    case ProjectionKind::Enum:
        return B.createUncheckedEnumData(Loc, Base,
                                         cast<EnumElementDecl>(getDecl()));
    case ProjectionKind::Class:
        return nullptr;
    }
}
Esempio n. 18
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/// Perform a foreign error check by testing whether the call result is nil.
static ManagedValue
emitResultIsNilErrorCheck(SILGenFunction &gen, SILLocation loc,
                          ManagedValue origResult, ManagedValue errorSlot,
                          bool suppressErrorCheck) {
  // Take local ownership of the optional result value.
  SILValue optionalResult = origResult.forward(gen);

  OptionalTypeKind optKind;
  SILType resultObjectType =
    optionalResult->getType().getAnyOptionalObjectType(gen.SGM.M, optKind);

  ASTContext &ctx = gen.getASTContext();

  // If we're suppressing the check, just do an unchecked take.
  if (suppressErrorCheck) {
    SILValue objectResult =
      gen.B.createUncheckedEnumData(loc, optionalResult,
                                    ctx.getOptionalSomeDecl(optKind));
    return gen.emitManagedRValueWithCleanup(objectResult);
  }

  // Switch on the optional result.
  SILBasicBlock *errorBB = gen.createBasicBlock(FunctionSection::Postmatter);
  SILBasicBlock *contBB = gen.createBasicBlock();
  gen.B.createSwitchEnum(loc, optionalResult, /*default*/ nullptr,
                         { { ctx.getOptionalSomeDecl(optKind), contBB },
                           { ctx.getOptionalNoneDecl(optKind), errorBB } });

  // Emit the error block.
  gen.emitForeignErrorBlock(loc, errorBB, errorSlot);

  // In the continuation block, take ownership of the now non-optional
  // result value.
  gen.B.emitBlock(contBB);
  SILValue objectResult = contBB->createBBArg(resultObjectType);
  return gen.emitManagedRValueWithCleanup(objectResult);
}
Esempio n. 19
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std::tuple<ManagedValue, SILType>
SILGenFunction::emitSiblingMethodRef(SILLocation loc,
                                     SILValue selfValue,
                                     SILDeclRef methodConstant,
                                     const SubstitutionMap &subMap) {
  SILValue methodValue;

  // If the method is dynamic, access it through runtime-hookable virtual
  // dispatch (viz. objc_msgSend for now).
  if (methodConstant.hasDecl()
      && methodConstant.getDecl()->isDynamic())
    methodValue = emitDynamicMethodRef(loc, methodConstant,
                                     SGM.Types.getConstantInfo(methodConstant));
  else
    methodValue = emitGlobalFunctionRef(loc, methodConstant);

  SILType methodTy = methodValue->getType();

  // Specialize the generic method.
  methodTy = methodTy.substGenericArgs(SGM.M, subMap);

  return std::make_tuple(ManagedValue::forUnmanaged(methodValue),
                         methodTy);
}
Esempio n. 20
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void SILGenFunction::emitClassConstructorAllocator(ConstructorDecl *ctor) {
  assert(!ctor->isFactoryInit() && "factories should not be emitted here");

  // Emit the prolog. Since we're just going to forward our args directly
  // to the initializer, don't allocate local variables for them.
  RegularLocation Loc(ctor);
  Loc.markAutoGenerated();

  // Forward the constructor arguments.
  // FIXME: Handle 'self' along with the other body patterns.
  SmallVector<SILValue, 8> args;
  bindParametersForForwarding(ctor->getParameterList(1), args);

  SILValue selfMetaValue = emitConstructorMetatypeArg(*this, ctor);

  // Allocate the "self" value.
  VarDecl *selfDecl = ctor->getImplicitSelfDecl();
  SILType selfTy = getLoweredType(selfDecl->getType());
  assert(selfTy.hasReferenceSemantics() &&
         "can't emit a value type ctor here");

  // Use alloc_ref to allocate the object.
  // TODO: allow custom allocation?
  // FIXME: should have a cleanup in case of exception
  auto selfClassDecl = ctor->getDeclContext()->getAsClassOrClassExtensionContext();

  SILValue selfValue;

  // Allocate the 'self' value.
  bool useObjCAllocation = usesObjCAllocator(selfClassDecl);

  if (ctor->isConvenienceInit() || ctor->hasClangNode()) {
    // For a convenience initializer or an initializer synthesized
    // for an Objective-C class, allocate using the metatype.
    SILValue allocArg = selfMetaValue;

    // When using Objective-C allocation, convert the metatype
    // argument to an Objective-C metatype.
    if (useObjCAllocation) {
      auto metaTy = allocArg->getType().castTo<MetatypeType>();
      metaTy = CanMetatypeType::get(metaTy.getInstanceType(),
                                    MetatypeRepresentation::ObjC);
      allocArg = B.createThickToObjCMetatype(Loc, allocArg,
                                             getLoweredType(metaTy));
    }

    selfValue = B.createAllocRefDynamic(Loc, allocArg, selfTy,
                                        useObjCAllocation, {}, {});
  } else {
    // For a designated initializer, we know that the static type being
    // allocated is the type of the class that defines the designated
    // initializer.
    selfValue = B.createAllocRef(Loc, selfTy, useObjCAllocation, false, {}, {});
  }
  args.push_back(selfValue);

  // Call the initializer. Always use the Swift entry point, which will be a
  // bridging thunk if we're calling ObjC.
  SILDeclRef initConstant =
    SILDeclRef(ctor,
               SILDeclRef::Kind::Initializer,
               SILDeclRef::ConstructAtBestResilienceExpansion,
               SILDeclRef::ConstructAtNaturalUncurryLevel,
               /*isObjC=*/false);

  ManagedValue initVal;
  SILType initTy;

  ArrayRef<Substitution> subs;
  // Call the initializer.
  ArrayRef<Substitution> forwardingSubs;
  if (auto *genericEnv = ctor->getGenericEnvironmentOfContext()) {
    auto *genericSig = ctor->getGenericSignatureOfContext();
    forwardingSubs = genericEnv->getForwardingSubstitutions(
        SGM.SwiftModule, genericSig);
  }
  std::tie(initVal, initTy, subs)
    = emitSiblingMethodRef(Loc, selfValue, initConstant, forwardingSubs);

  SILValue initedSelfValue = emitApplyWithRethrow(Loc, initVal.forward(*this),
                                                  initTy, subs, args);

  // Return the initialized 'self'.
  B.createReturn(ImplicitReturnLocation::getImplicitReturnLoc(Loc),
                 initedSelfValue);
}
Esempio n. 21
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ManagedValue SILGenFunction::emitExistentialErasure(
                            SILLocation loc,
                            CanType concreteFormalType,
                            const TypeLowering &concreteTL,
                            const TypeLowering &existentialTL,
                            ArrayRef<ProtocolConformanceRef> conformances,
                            SGFContext C,
                            llvm::function_ref<ManagedValue (SGFContext)> F,
                            bool allowEmbeddedNSError) {
  // Mark the needed conformances as used.
  for (auto conformance : conformances)
    SGM.useConformance(conformance);

  // If we're erasing to the 'Error' type, we might be able to get an NSError
  // representation more efficiently.
  auto &ctx = getASTContext();
  if (ctx.LangOpts.EnableObjCInterop && conformances.size() == 1 &&
      conformances[0].getRequirement() == ctx.getErrorDecl() &&
      ctx.getNSErrorDecl()) {
    auto nsErrorDecl = ctx.getNSErrorDecl();

    // If the concrete type is NSError or a subclass thereof, just erase it
    // directly.
    auto nsErrorType = nsErrorDecl->getDeclaredType()->getCanonicalType();
    if (nsErrorType->isExactSuperclassOf(concreteFormalType, nullptr)) {
      ManagedValue nsError =  F(SGFContext());
      if (nsErrorType != concreteFormalType) {
        nsError = ManagedValue(B.createUpcast(loc, nsError.getValue(),
                                              getLoweredType(nsErrorType)),
                               nsError.getCleanup());
      }
      return emitBridgedToNativeError(loc, nsError);
    }

    // If the concrete type is known to conform to _BridgedStoredNSError,
    // call the _nsError witness getter to extract the NSError directly,
    // then just erase the NSError.
    if (auto storedNSErrorConformance =
          SGM.getConformanceToBridgedStoredNSError(loc, concreteFormalType)) {
      auto nsErrorVar = SGM.getNSErrorRequirement(loc);
      if (!nsErrorVar) return emitUndef(loc, existentialTL.getLoweredType());

      SubstitutionList nsErrorVarSubstitutions;

      // Devirtualize.  Maybe this should be done implicitly by
      // emitPropertyLValue?
      if (storedNSErrorConformance->isConcrete()) {
        if (auto witnessVar = storedNSErrorConformance->getConcrete()
                                          ->getWitness(nsErrorVar, nullptr)) {
          nsErrorVar = cast<VarDecl>(witnessVar.getDecl());
          nsErrorVarSubstitutions = witnessVar.getSubstitutions();
        }
      }

      auto nativeError = F(SGFContext());

      WritebackScope writebackScope(*this);
      auto nsError =
        emitRValueForPropertyLoad(loc, nativeError, concreteFormalType,
                                  /*super*/ false, nsErrorVar,
                                  nsErrorVarSubstitutions,
                                  AccessSemantics::Ordinary, nsErrorType,
                                  SGFContext())
        .getAsSingleValue(*this, loc);

      return emitBridgedToNativeError(loc, nsError);
    }

    // Otherwise, if it's an archetype, try calling the _getEmbeddedNSError()
    // witness to try to dig out the embedded NSError.  But don't do this
    // when we're being called recursively.
    if (isa<ArchetypeType>(concreteFormalType) && allowEmbeddedNSError) {
      auto contBB = createBasicBlock();
      auto isNotPresentBB = createBasicBlock();
      auto isPresentBB = createBasicBlock();

      // Call swift_stdlib_getErrorEmbeddedNSError to attempt to extract an
      // NSError from the value.
      auto getEmbeddedNSErrorFn = SGM.getGetErrorEmbeddedNSError(loc);
      if (!getEmbeddedNSErrorFn)
        return emitUndef(loc, existentialTL.getLoweredType());

      Substitution getEmbeddedNSErrorSubstitutions[1] = {
        Substitution(concreteFormalType, conformances)
      };

      ManagedValue concreteValue = F(SGFContext());
      ManagedValue potentialNSError =
        emitApplyOfLibraryIntrinsic(loc,
                                    getEmbeddedNSErrorFn,
                                    getEmbeddedNSErrorSubstitutions,
                                    { concreteValue.copy(*this, loc) },
                                    SGFContext())
          .getAsSingleValue(*this, loc);

      // We're going to consume 'concreteValue' in exactly one branch,
      // so kill its cleanup now and recreate it on both branches.
      (void) concreteValue.forward(*this);

      // Check whether we got an NSError back.
      std::pair<EnumElementDecl*, SILBasicBlock*> cases[] = {
        { ctx.getOptionalSomeDecl(), isPresentBB },
        { ctx.getOptionalNoneDecl(), isNotPresentBB }
      };
      B.createSwitchEnum(loc, potentialNSError.forward(*this),
                         /*default*/ nullptr, cases);

      // If we did get an NSError, emit the existential erasure from that
      // NSError.
      B.emitBlock(isPresentBB);
      SILValue branchArg;
      {
        // Don't allow cleanups to escape the conditional block.
        FullExpr presentScope(Cleanups, CleanupLocation::get(loc));
        enterDestroyCleanup(concreteValue.getValue());

        // Receive the error value.  It's typed as an 'AnyObject' for
        // layering reasons, so perform an unchecked cast down to NSError.
        SILType anyObjectTy =
          potentialNSError.getType().getAnyOptionalObjectType();
        SILValue nsError = isPresentBB->createPHIArgument(
            anyObjectTy, ValueOwnershipKind::Owned);
        nsError = B.createUncheckedRefCast(loc, nsError, 
                                           getLoweredType(nsErrorType));

        branchArg = emitBridgedToNativeError(loc,
                                        emitManagedRValueWithCleanup(nsError))
                      .forward(*this);
      }
      B.createBranch(loc, contBB, branchArg);

      // If we did not get an NSError, just directly emit the existential.
      // Since this is a recursive call, make sure we don't end up in this
      // path again.
      B.emitBlock(isNotPresentBB);
      {
        FullExpr presentScope(Cleanups, CleanupLocation::get(loc));
        concreteValue = emitManagedRValueWithCleanup(concreteValue.getValue());
        branchArg = emitExistentialErasure(loc, concreteFormalType, concreteTL,
                                           existentialTL, conformances,
                                           SGFContext(),
                                           [&](SGFContext C) {
                                             return concreteValue;
                                           },
                                           /*allowEmbeddedNSError=*/false)
                      .forward(*this);
      }
      B.createBranch(loc, contBB, branchArg);

      // Continue.
      B.emitBlock(contBB);

      SILValue existentialResult = contBB->createPHIArgument(
          existentialTL.getLoweredType(), ValueOwnershipKind::Owned);
      return emitManagedRValueWithCleanup(existentialResult, existentialTL);
    }
  }

  switch (existentialTL.getLoweredType().getObjectType()
            .getPreferredExistentialRepresentation(SGM.M, concreteFormalType)) {
  case ExistentialRepresentation::None:
    llvm_unreachable("not an existential type");
  case ExistentialRepresentation::Metatype: {
    assert(existentialTL.isLoadable());

    SILValue metatype = F(SGFContext()).getUnmanagedValue();
    assert(metatype->getType().castTo<AnyMetatypeType>()->getRepresentation()
             == MetatypeRepresentation::Thick);

    auto upcast =
      B.createInitExistentialMetatype(loc, metatype,
                                      existentialTL.getLoweredType(),
                                      conformances);
    return ManagedValue::forUnmanaged(upcast);
  }
  case ExistentialRepresentation::Class: {
    assert(existentialTL.isLoadable());

    ManagedValue sub = F(SGFContext());
    SILValue v = B.createInitExistentialRef(loc,
                                            existentialTL.getLoweredType(),
                                            concreteFormalType,
                                            sub.getValue(),
                                            conformances);
    return ManagedValue(v, sub.getCleanup());
  }
  case ExistentialRepresentation::Boxed: {
    // Allocate the existential.
    auto *existential = B.createAllocExistentialBox(loc,
                                           existentialTL.getLoweredType(),
                                           concreteFormalType,
                                           conformances);
    auto *valueAddr = B.createProjectExistentialBox(loc,
                                           concreteTL.getLoweredType(),
                                           existential);
    // Initialize the concrete value in-place.
    ExistentialInitialization init(existential, valueAddr, concreteFormalType,
                                   ExistentialRepresentation::Boxed, *this);
    ManagedValue mv = F(SGFContext(&init));
    if (!mv.isInContext()) {
      mv.forwardInto(*this, loc, init.getAddress());
      init.finishInitialization(*this);
    }
    
    return emitManagedRValueWithCleanup(existential);
  }
  case ExistentialRepresentation::Opaque: {
  
    // If the concrete value is a pseudogeneric archetype, first erase it to
    // its upper bound.
    auto anyObjectProto = getASTContext()
      .getProtocol(KnownProtocolKind::AnyObject);
    auto anyObjectTy = anyObjectProto
      ? anyObjectProto->getDeclaredType()->getCanonicalType()
      : CanType();
    auto eraseToAnyObject =
    [&, concreteFormalType, F](SGFContext C) -> ManagedValue {
      auto concreteValue = F(SGFContext());
      auto anyObjectConformance = SGM.SwiftModule
        ->lookupConformance(concreteFormalType, anyObjectProto, nullptr);
      ProtocolConformanceRef buf[] = {
        *anyObjectConformance,
      };
      
      auto asAnyObject = B.createInitExistentialRef(loc,
                                  SILType::getPrimitiveObjectType(anyObjectTy),
                                  concreteFormalType,
                                  concreteValue.getValue(),
                                  getASTContext().AllocateCopy(buf));
      return ManagedValue(asAnyObject, concreteValue.getCleanup());
    };
    
    auto concreteTLPtr = &concreteTL;
    if (this->F.getLoweredFunctionType()->isPseudogeneric()) {
      if (anyObjectTy && concreteFormalType->is<ArchetypeType>()) {
        concreteFormalType = anyObjectTy;
        concreteTLPtr = &getTypeLowering(anyObjectTy);
        F = eraseToAnyObject;
      }
    }

    // Allocate the existential.
    SILValue existential =
      getBufferForExprResult(loc, existentialTL.getLoweredType(), C);

    // Allocate the concrete value inside the container.
    SILValue valueAddr = B.createInitExistentialAddr(
                            loc, existential,
                            concreteFormalType,
                            concreteTLPtr->getLoweredType(),
                            conformances);
    // Initialize the concrete value in-place.
    InitializationPtr init(
        new ExistentialInitialization(existential, valueAddr, concreteFormalType,
                                      ExistentialRepresentation::Opaque,
                                      *this));
    ManagedValue mv = F(SGFContext(init.get()));
    if (!mv.isInContext()) {
      mv.forwardInto(*this, loc, init->getAddress());
      init->finishInitialization(*this);
    }

    return manageBufferForExprResult(existential, existentialTL, C);
  }
  }

  llvm_unreachable("Unhandled ExistentialRepresentation in switch.");
}
Esempio n. 22
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/// AggregateAvailableValues - Given a bunch of primitive subelement values,
/// build out the right aggregate type (LoadTy) by emitting tuple and struct
/// instructions as necessary.
static SILValue
AggregateAvailableValues(SILInstruction *Inst, SILType LoadTy,
                         SILValue Address,
                         ArrayRef<std::pair<SILValue, unsigned>> AvailableValues,
                         unsigned FirstElt) {
  assert(LoadTy.isObject());
  SILModule &M = Inst->getModule();
  
  // Check to see if the requested value is fully available, as an aggregate.
  // This is a super-common case for single-element structs, but is also a
  // general answer for arbitrary structs and tuples as well.
  if (FirstElt < AvailableValues.size()) {  // #Elements may be zero.
    SILValue FirstVal = AvailableValues[FirstElt].first;
    if (FirstVal.isValid() && AvailableValues[FirstElt].second == 0 &&
        FirstVal.getType() == LoadTy) {
      // If the first element of this value is available, check any extra ones
      // before declaring success.
      bool AllMatch = true;
      for (unsigned i = 0, e = getNumSubElements(LoadTy, M); i != e; ++i)
        if (AvailableValues[FirstElt+i].first != FirstVal ||
            AvailableValues[FirstElt+i].second != i) {
          AllMatch = false;
          break;
        }
      
      if (AllMatch)
        return FirstVal;
    }
  }
  
  
  SILBuilderWithScope B(Inst);
  
  if (TupleType *TT = LoadTy.getAs<TupleType>()) {
    SmallVector<SILValue, 4> ResultElts;
    
    for (unsigned EltNo : indices(TT->getElements())) {
      SILType EltTy = LoadTy.getTupleElementType(EltNo);
      unsigned NumSubElt = getNumSubElements(EltTy, M);
      
      // If we are missing any of the available values in this struct element,
      // compute an address to load from.
      SILValue EltAddr;
      if (anyMissing(FirstElt, NumSubElt, AvailableValues))
        EltAddr = B.createTupleElementAddr(Inst->getLoc(), Address, EltNo,
                                           EltTy.getAddressType());
      
      ResultElts.push_back(AggregateAvailableValues(Inst, EltTy, EltAddr,
                                                    AvailableValues, FirstElt));
      FirstElt += NumSubElt;
    }
    
    return B.createTuple(Inst->getLoc(), LoadTy, ResultElts);
  }
  
  // Extract struct elements from fully referenceable structs.
  if (auto *SD = getFullyReferenceableStruct(LoadTy)) {
    SmallVector<SILValue, 4> ResultElts;
    
    for (auto *FD : SD->getStoredProperties()) {
      SILType EltTy = LoadTy.getFieldType(FD, M);
      unsigned NumSubElt = getNumSubElements(EltTy, M);
      
      // If we are missing any of the available values in this struct element,
      // compute an address to load from.
      SILValue EltAddr;
      if (anyMissing(FirstElt, NumSubElt, AvailableValues))
        EltAddr = B.createStructElementAddr(Inst->getLoc(), Address, FD,
                                            EltTy.getAddressType());
      
      ResultElts.push_back(AggregateAvailableValues(Inst, EltTy, EltAddr,
                                                    AvailableValues, FirstElt));
      FirstElt += NumSubElt;
    }
    return B.createStruct(Inst->getLoc(), LoadTy, ResultElts);
  }
  
  // Otherwise, we have a simple primitive.  If the value is available, use it,
  // otherwise emit a load of the value.
  auto Val = AvailableValues[FirstElt];
  if (!Val.first.isValid())
    return B.createLoad(Inst->getLoc(), Address);
  
  SILValue EltVal = ExtractSubElement(Val.first, Val.second, B, Inst->getLoc());
  // It must be the same type as LoadTy if available.
  assert(EltVal.getType() == LoadTy &&
         "Subelement types mismatch");
  return EltVal;
}
Esempio n. 23
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ManagedValue SILGenFunction::emitExistentialErasure(
                            SILLocation loc,
                            CanType concreteFormalType,
                            const TypeLowering &concreteTL,
                            const TypeLowering &existentialTL,
                            ArrayRef<ProtocolConformanceRef> conformances,
                            SGFContext C,
                            llvm::function_ref<ManagedValue (SGFContext)> F,
                            bool allowEmbeddedNSError) {
  // Mark the needed conformances as used.
  for (auto conformance : conformances)
    SGM.useConformance(conformance);

  // If we're erasing to the 'Error' type, we might be able to get an NSError
  // representation more efficiently.
  auto &ctx = getASTContext();
  auto nsError = ctx.getNSErrorDecl();
  if (allowEmbeddedNSError && nsError &&
      existentialTL.getSemanticType().getSwiftRValueType()->getAnyNominal() ==
        ctx.getErrorDecl()) {
    // Check whether the concrete type conforms to the _BridgedStoredNSError
    // protocol. In that case, call the _nsError witness getter to extract the
    // NSError directly.
    auto conformance =
      SGM.getConformanceToBridgedStoredNSError(loc, concreteFormalType);

    CanType nsErrorType =
      nsError->getDeclaredInterfaceType()->getCanonicalType();

    ProtocolConformanceRef nsErrorConformances[1] = {
      ProtocolConformanceRef(SGM.getNSErrorConformanceToError())
    };

    if (conformance && nsError && SGM.getNSErrorConformanceToError()) {
      if (auto witness =
            conformance->getWitness(SGM.getNSErrorRequirement(loc), nullptr)) {
        // Create a reference to the getter witness.
        SILDeclRef getter =
          getGetterDeclRef(cast<VarDecl>(witness.getDecl()),
                           /*isDirectAccessorUse=*/true);
        
        // Compute the substitutions.
        ArrayRef<Substitution> substitutions =
          concreteFormalType->gatherAllSubstitutions(
          SGM.SwiftModule, nullptr);

        // Emit the erasure, through the getter to _nsError.
        return emitExistentialErasure(
            loc, nsErrorType,
            getTypeLowering(nsErrorType),
            existentialTL,
            ctx.AllocateCopy(nsErrorConformances),
            C,
            [&](SGFContext innerC) -> ManagedValue {
              // Call the getter.
              return emitGetAccessor(loc, getter, substitutions,
                                     ArgumentSource(loc,
                                                    RValue(*this, loc,
                                                           concreteFormalType,
                                                           F(SGFContext()))),
                                     /*isSuper=*/false,
                                     /*isDirectAccessorUse=*/true,
                                     RValue(), innerC)
                .getAsSingleValue(*this, loc);
            });
      }
    }

    // Check whether the concrete type is an archetype. If so, call the
    // _getEmbeddedNSError() witness to try to dig out the embedded NSError.
    if (auto archetypeType = concreteFormalType->getAs<ArchetypeType>()) {
      if (std::find(archetypeType->getConformsTo().begin(),
                       archetypeType->getConformsTo().end(),
                       ctx.getErrorDecl())
            != archetypeType->getConformsTo().end()) {
        auto contBB = createBasicBlock();
        auto isNotPresentBB = createBasicBlock();
        auto isPresentBB = createBasicBlock();

        SILValue existentialResult =
          contBB->createBBArg(existentialTL.getLoweredType());

        ProtocolConformanceRef trivialErrorConformances[1] = {
          ProtocolConformanceRef(ctx.getErrorDecl())
        };

        Substitution substitutions[1] = {
          Substitution(concreteFormalType,
                       ctx.AllocateCopy(trivialErrorConformances))
        };

        // Call swift_stdlib_getErrorEmbeddedNSError to attempt to extract an
        // NSError from the value.
        ManagedValue concreteValue = F(SGFContext());
        ManagedValue potentialNSError =
          emitApplyOfLibraryIntrinsic(loc,
                                      SGM.getGetErrorEmbeddedNSError(loc),
                                      ctx.AllocateCopy(substitutions),
                                      { concreteValue },
                                      SGFContext())
            .getAsSingleValue(*this, loc);

        // Check whether we got an NSError back.
        SILValue hasNSError =
          emitDoesOptionalHaveValue(loc, potentialNSError.getValue());

        B.createCondBranch(loc, hasNSError, isPresentBB, isNotPresentBB);

        // If we did get an NSError, emit the existential erasure from that
        // NSError.
        B.emitBlock(isPresentBB);
        SILValue branchArg;
        {
          // Don't allow cleanups to escape the conditional block.
          FullExpr presentScope(Cleanups, CleanupLocation::get(loc));
          
          // Emit the existential erasure from the NSError.
          branchArg = emitExistentialErasure(
              loc, nsErrorType,
              getTypeLowering(nsErrorType),
              existentialTL,
              ctx.AllocateCopy(nsErrorConformances),
              C,
              [&](SGFContext innerC) -> ManagedValue {
                // Pull the NSError object out of the optional result.
                auto &inputTL = getTypeLowering(potentialNSError.getType());
                auto nsErrorValue =
                  emitUncheckedGetOptionalValueFrom(loc, potentialNSError,
                                                    inputTL);


                // Perform an unchecked cast down to NSError, because it was typed
                // as 'AnyObject' for layering reasons.
                return ManagedValue(B.createUncheckedRefCast(
                                      loc,
                                      nsErrorValue.getValue(),
                                      getLoweredType(nsErrorType)),
                                    nsErrorValue.getCleanup());

              }).forward(*this);
        }
        B.createBranch(loc, contBB, branchArg);

        // If we did not get an NSError, just directly emit the existential
        // (recursively).
        B.emitBlock(isNotPresentBB);
        branchArg = emitExistentialErasure(loc, concreteFormalType, concreteTL,
                                           existentialTL, conformances,
                                           SGFContext(), F,
                                           /*allowEmbeddedNSError=*/false)
                      .forward(*this);
        B.createBranch(loc, contBB, branchArg);

        // Continue.
        B.emitBlock(contBB);
        return emitManagedRValueWithCleanup(existentialResult, existentialTL);
      }
    }
  }

  switch (existentialTL.getLoweredType().getObjectType()
            .getPreferredExistentialRepresentation(SGM.M, concreteFormalType)) {
  case ExistentialRepresentation::None:
    llvm_unreachable("not an existential type");
  case ExistentialRepresentation::Metatype: {
    assert(existentialTL.isLoadable());

    SILValue metatype = F(SGFContext()).getUnmanagedValue();
    assert(metatype->getType().castTo<AnyMetatypeType>()->getRepresentation()
             == MetatypeRepresentation::Thick);

    auto upcast =
      B.createInitExistentialMetatype(loc, metatype,
                                      existentialTL.getLoweredType(),
                                      conformances);
    return ManagedValue::forUnmanaged(upcast);
  }
  case ExistentialRepresentation::Class: {
    assert(existentialTL.isLoadable());

    ManagedValue sub = F(SGFContext());
    SILValue v = B.createInitExistentialRef(loc,
                                            existentialTL.getLoweredType(),
                                            concreteFormalType,
                                            sub.getValue(),
                                            conformances);
    return ManagedValue(v, sub.getCleanup());
  }
  case ExistentialRepresentation::Boxed: {
    // Allocate the existential.
    auto *existential = B.createAllocExistentialBox(loc,
                                           existentialTL.getLoweredType(),
                                           concreteFormalType,
                                           conformances);
    auto *valueAddr = B.createProjectExistentialBox(loc,
                                           concreteTL.getLoweredType(),
                                           existential);
    // Initialize the concrete value in-place.
    InitializationPtr init(
        new ExistentialInitialization(existential, valueAddr, concreteFormalType,
                                      ExistentialRepresentation::Boxed,
                                      *this));
    ManagedValue mv = F(SGFContext(init.get()));
    if (!mv.isInContext()) {
      mv.forwardInto(*this, loc, init->getAddress());
      init->finishInitialization(*this);
    }
    
    return emitManagedRValueWithCleanup(existential);
  }
  case ExistentialRepresentation::Opaque: {
    // Allocate the existential.
    SILValue existential =
      getBufferForExprResult(loc, existentialTL.getLoweredType(), C);

    // Allocate the concrete value inside the container.
    SILValue valueAddr = B.createInitExistentialAddr(
                            loc, existential,
                            concreteFormalType,
                            concreteTL.getLoweredType(),
                            conformances);
    // Initialize the concrete value in-place.
    InitializationPtr init(
        new ExistentialInitialization(existential, valueAddr, concreteFormalType,
                                      ExistentialRepresentation::Opaque,
                                      *this));
    ManagedValue mv = F(SGFContext(init.get()));
    if (!mv.isInContext()) {
      mv.forwardInto(*this, loc, init->getAddress());
      init->finishInitialization(*this);
    }

    return manageBufferForExprResult(existential, existentialTL, C);
  }
  }
}
Esempio n. 24
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/// Generate a new apply of a function_ref to replace an apply of a
/// witness_method when we've determined the actual function we'll end
/// up calling.
static ApplySite devirtualizeWitnessMethod(ApplySite AI, SILFunction *F,
                                           ArrayRef<Substitution> Subs) {
  // We know the witness thunk and the corresponding set of substitutions
  // required to invoke the protocol method at this point.
  auto &Module = AI.getModule();

  // Collect all the required substitutions.
  //
  // The complete set of substitutions may be different, e.g. because the found
  // witness thunk F may have been created by a  specialization pass and have
  // additional generic parameters.
  SmallVector<Substitution, 16> NewSubstList(Subs.begin(), Subs.end());

  // Add the non-self-derived substitutions from the original application.
  ArrayRef<Substitution>  SubstList;
  SubstList = AI.getSubstitutionsWithoutSelfSubstitution();

  for (auto &origSub : SubstList)
    if (!origSub.getArchetype()->isSelfDerived())
      NewSubstList.push_back(origSub);

  // Figure out the exact bound type of the function to be called by
  // applying all substitutions.
  auto CalleeCanType = F->getLoweredFunctionType();
  auto SubstCalleeCanType = CalleeCanType->substGenericArgs(
    Module, Module.getSwiftModule(), NewSubstList);

  // Collect arguments from the apply instruction.
  auto Arguments = SmallVector<SILValue, 4>();

  auto ParamTypes = SubstCalleeCanType->getParameterSILTypes();

  // Iterate over the non self arguments and add them to the
  // new argument list, upcasting when required.
  SILBuilderWithScope B(AI.getInstruction());
  for (unsigned ArgN = 0, ArgE = AI.getNumArguments(); ArgN != ArgE; ++ArgN) {
    SILValue A = AI.getArgument(ArgN);
    auto ParamType = ParamTypes[ParamTypes.size() - AI.getNumArguments() + ArgN];
    if (A.getType() != ParamType)
      A = B.createUpcast(AI.getLoc(), A, ParamType);

    Arguments.push_back(A);
  }

  // Replace old apply instruction by a new apply instruction that invokes
  // the witness thunk.
  SILBuilderWithScope Builder(AI.getInstruction());
  SILLocation Loc = AI.getLoc();
  FunctionRefInst *FRI = Builder.createFunctionRef(Loc, F);

  auto SubstCalleeSILType = SILType::getPrimitiveObjectType(SubstCalleeCanType);
  auto ResultSILType = SubstCalleeCanType->getSILResult();
  ApplySite SAI;

  if (auto *A = dyn_cast<ApplyInst>(AI))
    SAI = Builder.createApply(Loc, FRI, SubstCalleeSILType,
                              ResultSILType, NewSubstList, Arguments,
                              A->isNonThrowing());
  if (auto *TAI = dyn_cast<TryApplyInst>(AI))
    SAI = Builder.createTryApply(Loc, FRI, SubstCalleeSILType,
                                 NewSubstList, Arguments,
                                 TAI->getNormalBB(), TAI->getErrorBB());
  if (auto *PAI = dyn_cast<PartialApplyInst>(AI))
    SAI = Builder.createPartialApply(Loc, FRI, SubstCalleeSILType,
                                     NewSubstList, Arguments, PAI->getType());

  NumWitnessDevirt++;
  return SAI;
}
Esempio n. 25
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DevirtualizationResult swift::tryDevirtualizeClassMethod(FullApplySite AI,
                                                   SILValue ClassInstance) {
  if (!canDevirtualizeClassMethod(AI, ClassInstance.getType()))
    return std::make_pair(nullptr, FullApplySite());
  return devirtualizeClassMethod(AI, ClassInstance);
}
Esempio n. 26
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/// \brief Devirtualize an apply of a class method.
///
/// \p AI is the apply to devirtualize.
/// \p ClassOrMetatype is a class value or metatype value that is the
///    self argument of the apply we will devirtualize.
/// return the result value of the new ApplyInst if created one or null.
DevirtualizationResult swift::devirtualizeClassMethod(FullApplySite AI,
                                                     SILValue ClassOrMetatype) {
  DEBUG(llvm::dbgs() << "    Trying to devirtualize : " << *AI.getInstruction());

  SILModule &Mod = AI.getModule();
  auto *CMI = cast<ClassMethodInst>(AI.getCallee());
  auto ClassOrMetatypeType = ClassOrMetatype.getType();
  auto *F = getTargetClassMethod(Mod, ClassOrMetatypeType, CMI->getMember());

  CanSILFunctionType GenCalleeType = F->getLoweredFunctionType();

  auto Subs = getSubstitutionsForCallee(Mod, GenCalleeType,
                                        ClassOrMetatypeType, AI);
  CanSILFunctionType SubstCalleeType = GenCalleeType;
  if (GenCalleeType->isPolymorphic())
    SubstCalleeType = GenCalleeType->substGenericArgs(Mod, Mod.getSwiftModule(), Subs);

  SILBuilderWithScope B(AI.getInstruction());
  FunctionRefInst *FRI = B.createFunctionRef(AI.getLoc(), F);

  // Create the argument list for the new apply, casting when needed
  // in order to handle covariant indirect return types and
  // contravariant argument types.
  llvm::SmallVector<SILValue, 8> NewArgs;
  auto Args = AI.getArguments();
  auto ParamTypes = SubstCalleeType->getParameterSILTypes();

  for (unsigned i = 0, e = Args.size() - 1; i != e; ++i)
    NewArgs.push_back(castValueToABICompatibleType(&B, AI.getLoc(), Args[i],
                                                   Args[i].getType(),
                                                   ParamTypes[i]).getValue());

  // Add the self argument, upcasting if required because we're
  // calling a base class's method.
  auto SelfParamTy = SubstCalleeType->getSelfParameter().getSILType();
  NewArgs.push_back(castValueToABICompatibleType(&B, AI.getLoc(),
                                                 ClassOrMetatype,
                                                 ClassOrMetatypeType,
                                                 SelfParamTy).getValue());

  // If we have a direct return type, make sure we use the subst callee return
  // type. If we have an indirect return type, AI's return type of the empty
  // tuple should be ok.
  SILType ResultTy = AI.getType();
  if (!SubstCalleeType->hasIndirectResult()) {
    ResultTy = SubstCalleeType->getSILResult();
  }

  SILType SubstCalleeSILType =
    SILType::getPrimitiveObjectType(SubstCalleeType);
  FullApplySite NewAI;

  SILBasicBlock *ResultBB = nullptr;
  SILBasicBlock *NormalBB = nullptr;
  SILValue ResultValue;
  bool ResultCastRequired = false;
  SmallVector<Operand *, 4> OriginalResultUses;

  if (!isa<TryApplyInst>(AI)) {
    NewAI = B.createApply(AI.getLoc(), FRI, SubstCalleeSILType, ResultTy,
                          Subs, NewArgs, cast<ApplyInst>(AI)->isNonThrowing());
    ResultValue = SILValue(NewAI.getInstruction(), 0);
  } else {
    auto *TAI = cast<TryApplyInst>(AI);
    // Create new normal and error BBs only if:
    // - re-using a BB would create a critical edge
    // - or, the result of the new apply would be of different
    //   type than the argument of the original normal BB.
    if (TAI->getNormalBB()->getSinglePredecessor())
      ResultBB = TAI->getNormalBB();
    else {
      ResultBB = B.getFunction().createBasicBlock();
      ResultBB->createBBArg(ResultTy);
    }

    NormalBB = TAI->getNormalBB();

    SILBasicBlock *ErrorBB = nullptr;
    if (TAI->getErrorBB()->getSinglePredecessor())
      ErrorBB = TAI->getErrorBB();
    else {
      ErrorBB = B.getFunction().createBasicBlock();
      ErrorBB->createBBArg(TAI->getErrorBB()->getBBArg(0)->getType());
    }

    NewAI = B.createTryApply(AI.getLoc(), FRI, SubstCalleeSILType,
                             Subs, NewArgs,
                             ResultBB, ErrorBB);
    if (ErrorBB != TAI->getErrorBB()) {
      B.setInsertionPoint(ErrorBB);
      B.createBranch(TAI->getLoc(), TAI->getErrorBB(),
                     {ErrorBB->getBBArg(0)});
    }

    // Does the result value need to be casted?
    ResultCastRequired = ResultTy != NormalBB->getBBArg(0)->getType();

    if (ResultBB != NormalBB)
      B.setInsertionPoint(ResultBB);
    else if (ResultCastRequired) {
      B.setInsertionPoint(NormalBB->begin());
      // Collect all uses, before casting.
      for (auto *Use : NormalBB->getBBArg(0)->getUses()) {
        OriginalResultUses.push_back(Use);
      }
      NormalBB->getBBArg(0)->replaceAllUsesWith(SILUndef::get(AI.getType(), Mod));
      NormalBB->replaceBBArg(0, ResultTy, nullptr);
    }

    // The result value is passed as a parameter to the normal block.
    ResultValue = ResultBB->getBBArg(0);
  }

  // Check if any casting is required for the return value.
  ResultValue = castValueToABICompatibleType(&B, NewAI.getLoc(), ResultValue,
                                             ResultTy, AI.getType()).getValue();

  DEBUG(llvm::dbgs() << "        SUCCESS: " << F->getName() << "\n");
  NumClassDevirt++;

  if (NormalBB) {
    if (NormalBB != ResultBB) {
      // If artificial normal BB was introduced, branch
      // to the original normal BB.
      B.createBranch(NewAI.getLoc(), NormalBB, { ResultValue });
    } else if (ResultCastRequired) {
      // Update all original uses by the new value.
      for(auto *Use: OriginalResultUses) {
        Use->set(ResultValue);
      }
    }
    return std::make_pair(NewAI.getInstruction(), NewAI);
  }

  // We need to return a pair of values here:
  // - the first one is the actual result of the devirtualized call, possibly
  //   casted into an appropriate type. This SILValue may be a BB arg, if it
  //   was a cast between optional types.
  // - the second one is the new apply site.
  return std::make_pair(ResultValue.getDef(), NewAI);
}
Esempio n. 27
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ManagedValue SILGenFunction::emitExistentialErasure(
                            SILLocation loc,
                            CanType concreteFormalType,
                            const TypeLowering &concreteTL,
                            const TypeLowering &existentialTL,
                            const ArrayRef<ProtocolConformance *> &conformances,
                            SGFContext C,
                            llvm::function_ref<ManagedValue (SGFContext)> F) {
  // Mark the needed conformances as used.
  for (auto *conformance : conformances)
    SGM.useConformance(conformance);

  switch (existentialTL.getLoweredType().getObjectType()
            .getPreferredExistentialRepresentation(SGM.M, concreteFormalType)) {
  case ExistentialRepresentation::None:
    llvm_unreachable("not an existential type");
  case ExistentialRepresentation::Metatype: {
    assert(existentialTL.isLoadable());

    SILValue metatype = F(SGFContext()).getUnmanagedValue();
    assert(metatype.getType().castTo<AnyMetatypeType>()->getRepresentation()
             == MetatypeRepresentation::Thick);

    auto upcast =
      B.createInitExistentialMetatype(loc, metatype,
                                      existentialTL.getLoweredType(),
                                      conformances);
    return ManagedValue::forUnmanaged(upcast);
  }
  case ExistentialRepresentation::Class: {
    assert(existentialTL.isLoadable());

    ManagedValue sub = F(SGFContext());
    SILValue v = B.createInitExistentialRef(loc,
                                            existentialTL.getLoweredType(),
                                            concreteFormalType,
                                            sub.getValue(),
                                            conformances);
    return ManagedValue(v, sub.getCleanup());
  }
  case ExistentialRepresentation::Boxed: {
    // Allocate the existential.
    auto box = B.createAllocExistentialBox(loc,
                                           existentialTL.getLoweredType(),
                                           concreteFormalType,
                                           concreteTL.getLoweredType(),
                                           conformances);
    auto existential = box->getExistentialResult();
    auto valueAddr = box->getValueAddressResult();

    // Initialize the concrete value in-place.
    InitializationPtr init(
        new ExistentialInitialization(existential, valueAddr, concreteFormalType,
                                      ExistentialRepresentation::Boxed,
                                      *this));
    ManagedValue mv = F(SGFContext(init.get()));
    if (!mv.isInContext()) {
      mv.forwardInto(*this, loc, init->getAddress());
      init->finishInitialization(*this);
    }
    
    return emitManagedRValueWithCleanup(existential);
  }
  case ExistentialRepresentation::Opaque: {
    // Allocate the existential.
    SILValue existential =
      getBufferForExprResult(loc, existentialTL.getLoweredType(), C);

    // Allocate the concrete value inside the container.
    SILValue valueAddr = B.createInitExistentialAddr(
                            loc, existential,
                            concreteFormalType,
                            concreteTL.getLoweredType(),
                            conformances);
    // Initialize the concrete value in-place.
    InitializationPtr init(
        new ExistentialInitialization(existential, valueAddr, concreteFormalType,
                                      ExistentialRepresentation::Opaque,
                                      *this));
    ManagedValue mv = F(SGFContext(init.get()));
    if (!mv.isInContext()) {
      mv.forwardInto(*this, loc, init->getAddress());
      init->finishInitialization(*this);
    }

    return manageBufferForExprResult(existential, existentialTL, C);
  }
  }
}
Esempio n. 28
0
void SILGenFunction::emitArtificialTopLevel(ClassDecl *mainClass) {
  // Load argc and argv from the entry point arguments.
  SILValue argc = F.begin()->getBBArg(0);
  SILValue argv = F.begin()->getBBArg(1);

  switch (mainClass->getArtificialMainKind()) {
  case ArtificialMainKind::UIApplicationMain: {
    // Emit a UIKit main.
    // return UIApplicationMain(C_ARGC, C_ARGV, nil, ClassName);

    CanType NSStringTy = SGM.Types.getNSStringType();
    CanType OptNSStringTy
      = OptionalType::get(NSStringTy)->getCanonicalType();
    CanType IUOptNSStringTy
      = ImplicitlyUnwrappedOptionalType::get(NSStringTy)->getCanonicalType();

    // Look up UIApplicationMain.
    // FIXME: Doing an AST lookup here is gross and not entirely sound;
    // we're getting away with it because the types are guaranteed to already
    // be imported.
    ASTContext &ctx = getASTContext();
    Module *UIKit = ctx.getLoadedModule(ctx.getIdentifier("UIKit"));
    SmallVector<ValueDecl *, 1> results;
    UIKit->lookupQualified(UIKit->getDeclaredType(),
                           ctx.getIdentifier("UIApplicationMain"),
                           NL_QualifiedDefault,
                           /*resolver*/nullptr,
                           results);
    assert(!results.empty() && "couldn't find UIApplicationMain in UIKit");
    assert(results.size() == 1 && "more than one UIApplicationMain?");

    SILDeclRef mainRef{results.front(), ResilienceExpansion::Minimal,
                       SILDeclRef::ConstructAtNaturalUncurryLevel,
                       /*isForeign*/true};
    auto UIApplicationMainFn = SGM.M.getOrCreateFunction(mainClass, mainRef,
                                                         NotForDefinition);
    auto fnTy = UIApplicationMainFn->getLoweredFunctionType();

    // Get the class name as a string using NSStringFromClass.
    CanType mainClassTy = mainClass->getDeclaredTypeInContext()->getCanonicalType();
    CanType mainClassMetaty = CanMetatypeType::get(mainClassTy,
                                                   MetatypeRepresentation::ObjC);
    ProtocolDecl *anyObjectProtocol =
      ctx.getProtocol(KnownProtocolKind::AnyObject);
    auto mainClassAnyObjectConformance = ProtocolConformanceRef(
      *SGM.M.getSwiftModule()->lookupConformance(mainClassTy, anyObjectProtocol,
                                                nullptr));
    CanType anyObjectTy = anyObjectProtocol
      ->getDeclaredTypeInContext()
      ->getCanonicalType();
    CanType anyObjectMetaTy = CanExistentialMetatypeType::get(anyObjectTy,
                                                  MetatypeRepresentation::ObjC);

    auto NSStringFromClassType = SILFunctionType::get(nullptr,
                  SILFunctionType::ExtInfo()
                    .withRepresentation(SILFunctionType::Representation::
                                        CFunctionPointer),
                  ParameterConvention::Direct_Unowned,
                  SILParameterInfo(anyObjectMetaTy,
                                   ParameterConvention::Direct_Unowned),
                  SILResultInfo(OptNSStringTy,
                                ResultConvention::Autoreleased),
                  /*error result*/ None,
                  ctx);
    auto NSStringFromClassFn
      = SGM.M.getOrCreateFunction(mainClass, "NSStringFromClass",
                                  SILLinkage::PublicExternal,
                                  NSStringFromClassType,
                                  IsBare, IsTransparent, IsNotFragile);
    auto NSStringFromClass = B.createFunctionRef(mainClass, NSStringFromClassFn);
    SILValue metaTy = B.createMetatype(mainClass,
                             SILType::getPrimitiveObjectType(mainClassMetaty));
    metaTy = B.createInitExistentialMetatype(mainClass, metaTy,
                          SILType::getPrimitiveObjectType(anyObjectMetaTy),
                          ctx.AllocateCopy(
                            llvm::makeArrayRef(mainClassAnyObjectConformance)));
    SILValue optName = B.createApply(mainClass,
                               NSStringFromClass,
                               NSStringFromClass->getType(),
                               SILType::getPrimitiveObjectType(OptNSStringTy),
                               {}, metaTy);

    // Fix up the string parameters to have the right type.
    SILType nameArgTy = fnTy->getSILArgumentType(3);
    assert(nameArgTy == fnTy->getSILArgumentType(2));
    auto managedName = ManagedValue::forUnmanaged(optName);
    SILValue nilValue;
    if (optName->getType() == nameArgTy) {
      nilValue = getOptionalNoneValue(mainClass,
                                      getTypeLowering(OptNSStringTy));
    } else {
      assert(nameArgTy.getSwiftRValueType() == IUOptNSStringTy);
      nilValue = getOptionalNoneValue(mainClass,
                                      getTypeLowering(IUOptNSStringTy));
      managedName = emitOptionalToOptional(
          mainClass, managedName,
          SILType::getPrimitiveObjectType(IUOptNSStringTy),
          [](SILGenFunction &, SILLocation, ManagedValue input, SILType) {
        return input;
      });
    }

    // Fix up argv to have the right type.
    auto argvTy = fnTy->getSILArgumentType(1);

    SILType unwrappedTy = argvTy;
    if (Type innerTy = argvTy.getSwiftRValueType()->getAnyOptionalObjectType()){
      auto canInnerTy = innerTy->getCanonicalType();
      unwrappedTy = SILType::getPrimitiveObjectType(canInnerTy);
    }

    auto managedArgv = ManagedValue::forUnmanaged(argv);

    if (unwrappedTy != argv->getType()) {
      auto converted =
          emitPointerToPointer(mainClass, managedArgv,
                               argv->getType().getSwiftRValueType(),
                               unwrappedTy.getSwiftRValueType());
      managedArgv = std::move(converted).getAsSingleValue(*this, mainClass);
    }

    if (unwrappedTy != argvTy) {
      managedArgv = getOptionalSomeValue(mainClass, managedArgv,
                                         getTypeLowering(argvTy));
    }

    auto UIApplicationMain = B.createFunctionRef(mainClass, UIApplicationMainFn);

    SILValue args[] = {argc, managedArgv.getValue(), nilValue,
                       managedName.getValue()};

    B.createApply(mainClass, UIApplicationMain,
                  UIApplicationMain->getType(),
                  argc->getType(), {}, args);
    SILValue r = B.createIntegerLiteral(mainClass,
                        SILType::getBuiltinIntegerType(32, ctx), 0);
    auto rType = F.getLoweredFunctionType()->getSingleResult().getSILType();
    if (r->getType() != rType)
      r = B.createStruct(mainClass, rType, r);

    Cleanups.emitCleanupsForReturn(mainClass);
    B.createReturn(mainClass, r);
    return;
  }

  case ArtificialMainKind::NSApplicationMain: {
    // Emit an AppKit main.
    // return NSApplicationMain(C_ARGC, C_ARGV);

    SILParameterInfo argTypes[] = {
      SILParameterInfo(argc->getType().getSwiftRValueType(),
                       ParameterConvention::Direct_Unowned),
      SILParameterInfo(argv->getType().getSwiftRValueType(),
                       ParameterConvention::Direct_Unowned),
    };
    auto NSApplicationMainType = SILFunctionType::get(nullptr,
                  SILFunctionType::ExtInfo()
                    // Should be C calling convention, but NSApplicationMain
                    // has an overlay to fix the type of argv.
                    .withRepresentation(SILFunctionType::Representation::Thin),
                  ParameterConvention::Direct_Unowned,
                  argTypes,
                  SILResultInfo(argc->getType().getSwiftRValueType(),
                                ResultConvention::Unowned),
                  /*error result*/ None,
                  getASTContext());

    auto NSApplicationMainFn
      = SGM.M.getOrCreateFunction(mainClass, "NSApplicationMain",
                                  SILLinkage::PublicExternal,
                                  NSApplicationMainType,
                                  IsBare, IsTransparent, IsNotFragile);

    auto NSApplicationMain = B.createFunctionRef(mainClass, NSApplicationMainFn);
    SILValue args[] = { argc, argv };

    B.createApply(mainClass, NSApplicationMain,
                  NSApplicationMain->getType(),
                  argc->getType(), {}, args);
    SILValue r = B.createIntegerLiteral(mainClass,
                        SILType::getBuiltinIntegerType(32, getASTContext()), 0);
    auto rType = F.getLoweredFunctionType()->getSingleResult().getSILType();
    if (r->getType() != rType)
      r = B.createStruct(mainClass, rType, r);
    B.createReturn(mainClass, r);
    return;
  }
  }
}
Esempio n. 29
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void SILGenFunction::emitValueConstructor(ConstructorDecl *ctor) {
  MagicFunctionName = SILGenModule::getMagicFunctionName(ctor);

  if (ctor->isMemberwiseInitializer())
    return emitImplicitValueConstructor(*this, ctor);

  // True if this constructor delegates to a peer constructor with self.init().
  bool isDelegating = ctor->getDelegatingOrChainedInitKind(nullptr) ==
    ConstructorDecl::BodyInitKind::Delegating;

  // Get the 'self' decl and type.
  VarDecl *selfDecl = ctor->getImplicitSelfDecl();
  auto &lowering = getTypeLowering(selfDecl->getType()->getInOutObjectType());
  SILType selfTy = lowering.getLoweredType();
  (void)selfTy;
  assert(!selfTy.getClassOrBoundGenericClass()
         && "can't emit a class ctor here");

  // Allocate the local variable for 'self'.
  emitLocalVariableWithCleanup(selfDecl, false)->finishInitialization(*this);
  
  // Mark self as being uninitialized so that DI knows where it is and how to
  // check for it.
  SILValue selfLV;
  {
    auto &SelfVarLoc = VarLocs[selfDecl];
    auto MUIKind =  isDelegating ? MarkUninitializedInst::DelegatingSelf
                                 : MarkUninitializedInst::RootSelf;
    selfLV = B.createMarkUninitialized(selfDecl, SelfVarLoc.value, MUIKind);
    SelfVarLoc.value = selfLV;
  }
  
  // Emit the prolog.
  emitProlog(ctor->getParameterList(1), ctor->getResultType(), ctor,
             ctor->hasThrows());
  emitConstructorMetatypeArg(*this, ctor);

  // Create a basic block to jump to for the implicit 'self' return.
  // We won't emit this until after we've emitted the body.
  // The epilog takes a void return because the return of 'self' is implicit.
  prepareEpilog(Type(), ctor->hasThrows(), CleanupLocation(ctor));

  // If the constructor can fail, set up an alternative epilog for constructor
  // failure.
  SILBasicBlock *failureExitBB = nullptr;
  SILArgument *failureExitArg = nullptr;
  auto &resultLowering = getTypeLowering(ctor->getResultType());

  if (ctor->getFailability() != OTK_None) {
    SILBasicBlock *failureBB = createBasicBlock(FunctionSection::Postmatter);

    // On failure, we'll clean up everything (except self, which should have
    // been cleaned up before jumping here) and return nil instead.
    SavedInsertionPoint savedIP(*this, failureBB, FunctionSection::Postmatter);
    failureExitBB = createBasicBlock();
    Cleanups.emitCleanupsForReturn(ctor);
    // Return nil.
    if (lowering.isAddressOnly()) {
      // Inject 'nil' into the indirect return.
      assert(F.getIndirectResults().size() == 1);
      B.createInjectEnumAddr(ctor, F.getIndirectResults()[0],
                             getASTContext().getOptionalNoneDecl());
      B.createBranch(ctor, failureExitBB);

      B.setInsertionPoint(failureExitBB);
      B.createReturn(ctor, emitEmptyTuple(ctor));
    } else {
      // Pass 'nil' as the return value to the exit BB.
      failureExitArg = new (F.getModule())
        SILArgument(failureExitBB, resultLowering.getLoweredType());
      SILValue nilResult =
        B.createEnum(ctor, {}, getASTContext().getOptionalNoneDecl(),
                     resultLowering.getLoweredType());
      B.createBranch(ctor, failureExitBB, nilResult);

      B.setInsertionPoint(failureExitBB);
      B.createReturn(ctor, failureExitArg);
    }

    FailDest = JumpDest(failureBB, Cleanups.getCleanupsDepth(), ctor);
  }

  // If this is not a delegating constructor, emit member initializers.
  if (!isDelegating) {
    auto *dc = ctor->getDeclContext();
    auto *nominal = dc->getAsNominalTypeOrNominalTypeExtensionContext();
    emitMemberInitializers(dc, selfDecl, nominal);
  }

  emitProfilerIncrement(ctor->getBody());
  // Emit the constructor body.
  emitStmt(ctor->getBody());

  
  // Build a custom epilog block, since the AST representation of the
  // constructor decl (which has no self in the return type) doesn't match the
  // SIL representation.
  SILValue selfValue;
  {
    SavedInsertionPoint savedIP(*this, ReturnDest.getBlock());
    assert(B.getInsertionBB()->empty() && "Epilog already set up?");
    
    auto cleanupLoc = CleanupLocation::get(ctor);
    
    if (!lowering.isAddressOnly()) {
      // Otherwise, load and return the final 'self' value.
      selfValue =
          B.createLoad(cleanupLoc, selfLV, LoadOwnershipQualifier::Unqualified);

      // Emit a retain of the loaded value, since we return it +1.
      lowering.emitCopyValue(B, cleanupLoc, selfValue);

      // Inject the self value into an optional if the constructor is failable.
      if (ctor->getFailability() != OTK_None) {
        selfValue = B.createEnum(ctor, selfValue,
                                 getASTContext().getOptionalSomeDecl(),
                                 getLoweredLoadableType(ctor->getResultType()));
      }
    } else {
      // If 'self' is address-only, copy 'self' into the indirect return slot.
      assert(F.getIndirectResults().size() == 1 &&
             "no indirect return for address-only ctor?!");

      // Get the address to which to store the result.
      SILValue completeReturnAddress = F.getIndirectResults()[0];
      SILValue returnAddress;
      switch (ctor->getFailability()) {
      // For non-failable initializers, store to the return address directly.
      case OTK_None:
        returnAddress = completeReturnAddress;
        break;
      // If this is a failable initializer, project out the payload.
      case OTK_Optional:
      case OTK_ImplicitlyUnwrappedOptional:
        returnAddress = B.createInitEnumDataAddr(ctor, completeReturnAddress,
                                       getASTContext().getOptionalSomeDecl(),
                                                 selfLV->getType());
        break;
      }
      
      // We have to do a non-take copy because someone else may be using the
      // box (e.g. someone could have closed over it).
      B.createCopyAddr(cleanupLoc, selfLV, returnAddress,
                       IsNotTake, IsInitialization);
      
      // Inject the enum tag if the result is optional because of failability.
      if (ctor->getFailability() != OTK_None) {
        // Inject the 'Some' tag.
        B.createInjectEnumAddr(ctor, completeReturnAddress,
                               getASTContext().getOptionalSomeDecl());
      }
    }
  }
  
  // Finally, emit the epilog and post-matter.
  auto returnLoc = emitEpilog(ctor, /*UsesCustomEpilog*/true);

  // Finish off the epilog by returning.  If this is a failable ctor, then we
  // actually jump to the failure epilog to keep the invariant that there is
  // only one SIL return instruction per SIL function.
  if (B.hasValidInsertionPoint()) {
    if (!failureExitBB) {
      // If we're not returning self, then return () since we're returning Void.
      if (!selfValue) {
        SILLocation loc(ctor);
        loc.markAutoGenerated();
        selfValue = emitEmptyTuple(loc);
      }
      
      B.createReturn(returnLoc, selfValue);
    } else {
      if (selfValue)
        B.createBranch(returnLoc, failureExitBB, selfValue);
      else
        B.createBranch(returnLoc, failureExitBB);
    }
  }
}
Esempio n. 30
0
void SILGenFunction::emitCurryThunk(ValueDecl *vd,
                                    SILDeclRef from, SILDeclRef to) {
  SmallVector<SILValue, 8> curriedArgs;

  unsigned paramCount = from.uncurryLevel + 1;

  if (isa<ConstructorDecl>(vd) || isa<EnumElementDecl>(vd)) {
    // The first body parameter pattern for a constructor specifies the
    // "self" instance, but the constructor is invoked from outside on a
    // metatype.
    assert(from.uncurryLevel == 0 && to.uncurryLevel == 1
           && "currying constructor at level other than one?!");
    F.setBare(IsBare);
    auto selfMetaTy = vd->getType()->getAs<AnyFunctionType>()->getInput();
    auto metatypeVal = new (F.getModule()) SILArgument(F.begin(),
                                            getLoweredLoadableType(selfMetaTy));
    curriedArgs.push_back(metatypeVal);

  } else if (auto fd = dyn_cast<AbstractFunctionDecl>(vd)) {
    // Forward implicit closure context arguments.
    bool hasCaptures = fd->getCaptureInfo().hasLocalCaptures();
    if (hasCaptures)
      --paramCount;

    // Forward the curried formal arguments.
    auto forwardedPatterns = fd->getParameterLists().slice(0, paramCount);
    for (auto *paramPattern : reversed(forwardedPatterns))
      bindParametersForForwarding(paramPattern, curriedArgs);

    // Forward captures.
    if (hasCaptures) {
      auto captureInfo = SGM.Types.getLoweredLocalCaptures(fd);
      for (auto capture : captureInfo.getCaptures())
        forwardCaptureArgs(*this, curriedArgs, capture);
    }
  } else {
    llvm_unreachable("don't know how to curry this decl");
  }

  // Forward substitutions.
  ArrayRef<Substitution> subs;
  if (auto gp = getConstantInfo(to).ContextGenericParams) {
    subs = gp->getForwardingSubstitutions(getASTContext());
  }

  SILValue toFn = getNextUncurryLevelRef(*this, vd, to, from.isDirectReference,
                                         curriedArgs, subs);
  SILType resultTy
    = SGM.getConstantType(from).castTo<SILFunctionType>()
         ->getSingleResult().getSILType();
  resultTy = F.mapTypeIntoContext(resultTy);
  auto toTy = toFn->getType();

  // Forward archetypes and specialize if the function is generic.
  if (!subs.empty()) {
    auto toFnTy = toFn->getType().castTo<SILFunctionType>();
    toTy = getLoweredLoadableType(
              toFnTy->substGenericArgs(SGM.M, SGM.SwiftModule, subs));
  }

  // Partially apply the next uncurry level and return the result closure.
  auto closureTy =
    SILGenBuilder::getPartialApplyResultType(toFn->getType(), curriedArgs.size(),
                                             SGM.M, subs);
  SILInstruction *toClosure =
    B.createPartialApply(vd, toFn, toTy, subs, curriedArgs, closureTy);
  if (resultTy != closureTy)
    toClosure = B.createConvertFunction(vd, toClosure, resultTy);
  B.createReturn(ImplicitReturnLocation::getImplicitReturnLoc(vd), toClosure);
}