| //===--- GenKeyPath.cpp - IRGen support for key path objects --------------===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See https://swift.org/LICENSE.txt for license information |
| // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file contains code for emitting key path patterns, which can be used |
| // by the standard library to instantiate key path objects. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "ConstantBuilder.h" |
| #include "Explosion.h" |
| #include "GenClass.h" |
| #include "GenDecl.h" |
| #include "GenMeta.h" |
| #include "GenProto.h" |
| #include "GenStruct.h" |
| #include "GenericRequirement.h" |
| #include "IRGenDebugInfo.h" |
| #include "IRGenFunction.h" |
| #include "IRGenModule.h" |
| #include "ProtocolInfo.h" |
| #include "StructLayout.h" |
| #include "llvm/ADT/SetVector.h" |
| #include "llvm/IR/Module.h" |
| #include "swift/SIL/SILInstruction.h" |
| #include "swift/SIL/SILLocation.h" |
| #include "swift/SIL/TypeLowering.h" |
| #include "swift/ABI/KeyPath.h" |
| #include "swift/ABI/HeapObject.h" |
| #include "swift/AST/ASTContext.h" |
| #include "swift/AST/DiagnosticEngine.h" |
| #include "swift/AST/DiagnosticsIRGen.h" |
| #include "swift/AST/GenericEnvironment.h" |
| #include "swift/AST/Types.h" |
| #include "swift/IRGen/Linking.h" |
| |
| using namespace swift; |
| using namespace irgen; |
| |
| enum GetterOrSetter { |
| Getter, |
| Setter, |
| }; |
| |
| static llvm::Function * |
| getAccessorForComputedComponent(IRGenModule &IGM, |
| const KeyPathPatternComponent &component, |
| GetterOrSetter whichAccessor, |
| GenericEnvironment *genericEnv, |
| ArrayRef<GenericRequirement> requirements) { |
| SILFunction *accessor; |
| switch (whichAccessor) { |
| case Getter: |
| accessor = component.getComputedPropertyGetter(); |
| break; |
| case Setter: |
| accessor = component.getComputedPropertySetter(); |
| break; |
| } |
| |
| auto accessorFn = IGM.getAddrOfSILFunction(accessor, NotForDefinition); |
| |
| // If the accessor is not generic, we can use it as is. |
| if (requirements.empty()) { |
| return accessorFn; |
| } |
| |
| auto accessorFnTy = accessorFn->getType()->getPointerElementType(); |
| |
| // Otherwise, we need a thunk to unmarshal the generic environment from the |
| // argument area. It'd be nice to have a good way to represent this |
| // directly in SIL, of course... |
| auto thunkType = llvm::FunctionType::get( |
| IGM.VoidTy, |
| { /*sret or newValue*/ accessorFnTy->getFunctionParamType(0), |
| /*base*/ accessorFnTy->getFunctionParamType(1), |
| /*arg*/ IGM.Int8PtrTy }, |
| /*vararg*/ false); |
| const char *thunkName; |
| unsigned numArgsToForward = 2; |
| switch (whichAccessor) { |
| case Getter: |
| thunkName = "keypath_get"; |
| break; |
| case Setter: |
| thunkName = "keypath_set"; |
| break; |
| } |
| |
| auto accessorThunk = llvm::Function::Create(thunkType, |
| llvm::GlobalValue::PrivateLinkage, thunkName, IGM.getModule()); |
| accessorThunk->setAttributes(IGM.constructInitialAttributes()); |
| // Original accessor's args should be @in or @out, meaning they won't be |
| // captured or aliased. |
| accessorThunk->addAttribute(1, llvm::Attribute::NoCapture); |
| accessorThunk->addAttribute(1, llvm::Attribute::NoAlias); |
| accessorThunk->addAttribute(2, llvm::Attribute::NoCapture); |
| accessorThunk->addAttribute(2, llvm::Attribute::NoAlias); |
| // Getter's output is sret. |
| if (whichAccessor == Getter) |
| accessorThunk->addAttribute(1, llvm::Attribute::StructRet); |
| accessorThunk->setCallingConv(IGM.SwiftCC); |
| |
| { |
| IRGenFunction IGF(IGM, accessorThunk); |
| if (IGM.DebugInfo) |
| IGM.DebugInfo->emitArtificialFunction(IGF, accessorThunk); |
| |
| auto params = IGF.collectParameters(); |
| Explosion forwardedArgs; |
| forwardedArgs.add(params.claim(numArgsToForward)); |
| |
| // The generic environment is marshaled into the beginning of the component |
| // argument area inside the instance. Bind the generic information out of |
| // the buffer, and advance past it. |
| auto componentArgsBuf = params.claimNext(); |
| bindFromGenericRequirementsBuffer(IGF, requirements, |
| Address(componentArgsBuf, IGM.getPointerAlignment()), |
| [&](CanType t) { |
| if (!genericEnv) |
| return t; |
| return genericEnv->mapTypeIntoContext(t)->getCanonicalType(); |
| }); |
| |
| /* TODO: If the underlying accessor wants index arguments, advance the |
| * pointer past the generic requirements here to pass down. */ |
| |
| // Use the bound generic metadata to form a call to the original generic |
| // accessor. |
| WitnessMetadata witnessMetadata; |
| auto forwardingSubs = genericEnv->getGenericSignature()->getSubstitutionMap( |
| genericEnv->getForwardingSubstitutions()); |
| emitPolymorphicArguments(IGF, accessor->getLoweredFunctionType(), |
| forwardingSubs, |
| &witnessMetadata, |
| forwardedArgs); |
| auto call = IGF.Builder.CreateCall(accessorFn, forwardedArgs.claimAll()); |
| if (whichAccessor == Getter) |
| call->addAttribute(1, llvm::Attribute::StructRet); |
| |
| IGF.Builder.CreateRetVoid(); |
| } |
| |
| return accessorThunk; |
| } |
| |
| static llvm::Constant * |
| getLayoutFunctionForComputedComponent(IRGenModule &IGM, |
| const KeyPathPatternComponent &component, |
| GenericEnvironment *genericEnv, |
| ArrayRef<GenericRequirement> requirements) { |
| // Generate a function that returns the expected size and alignment necessary |
| // to store captured generic context and subscript index arguments. |
| auto retTy = llvm::StructType::get(IGM.getLLVMContext(), |
| {IGM.SizeTy, IGM.SizeTy}); |
| auto fnTy = llvm::FunctionType::get( |
| retTy, { IGM.Int8PtrTy }, /*vararg*/ false); |
| |
| auto layoutFn = llvm::Function::Create(fnTy, |
| llvm::GlobalValue::PrivateLinkage, "keypath_get_arg_layout", IGM.getModule()); |
| |
| { |
| IRGenFunction IGF(IGM, layoutFn); |
| // TODO: We would need to unmarshal generic arguments to be able to |
| // compute the layout of dependent subscript indexes. |
| (void)IGF.collectParameters().claimNext(); |
| |
| // Base size is one pointer for each generic requirement; base alignment |
| // is pointer alignment. |
| llvm::Value *size = llvm::ConstantInt::get(IGM.SizeTy, |
| IGM.getPointerSize().getValue() * requirements.size()); |
| llvm::Value *alignMask = llvm::ConstantInt::get(IGM.SizeTy, |
| IGM.getPointerAlignment().getValue() - 1); |
| |
| // TODO: Combine layout of captured index values |
| |
| llvm::Value *retValue = IGF.Builder.CreateInsertValue( |
| llvm::UndefValue::get(retTy), size, 0); |
| retValue = IGF.Builder.CreateInsertValue( |
| retValue, alignMask, 1); |
| |
| IGF.Builder.CreateRet(retValue); |
| } |
| |
| return layoutFn; |
| } |
| |
| static llvm::Constant * |
| getWitnessTableForComputedComponent(IRGenModule &IGM, |
| const KeyPathPatternComponent &component, |
| GenericEnvironment *genericEnv, |
| ArrayRef<GenericRequirement> requirements) { |
| // If the only thing we're capturing is generic environment, then we can |
| // use a prefab witness table from the runtime. |
| // TODO: If there were subscript indexes, we'd need to generate something. |
| if (auto existing = |
| IGM.Module.getNamedGlobal("swift_keyPathGenericWitnessTable")) |
| return existing; |
| |
| auto linkInfo = LinkInfo::get(IGM, "swift_keyPathGenericWitnessTable", |
| SILLinkage::PublicExternal, |
| /*fragile*/ false, |
| /*sil only*/ false, |
| NotForDefinition, |
| /*weak imported*/ false); |
| |
| return createVariable(IGM, linkInfo, |
| IGM.Int8PtrTy, IGM.getPointerAlignment()); |
| } |
| |
| static llvm::Constant * |
| getInitializerForComputedComponent(IRGenModule &IGM, |
| const KeyPathPatternComponent &component, |
| GenericEnvironment *genericEnv, |
| ArrayRef<GenericRequirement> requirements) { |
| auto fnTy = llvm::FunctionType::get(IGM.VoidTy, |
| { /*src*/ IGM.Int8PtrTy, |
| /*dest*/ IGM.Int8PtrTy }, /*vararg*/ false); |
| |
| auto initFn = llvm::Function::Create(fnTy, |
| llvm::GlobalValue::PrivateLinkage, "keypath_arg_init", IGM.getModule()); |
| |
| { |
| IRGenFunction IGF(IGM, initFn); |
| auto params = IGF.collectParameters(); |
| auto src = params.claimNext(); |
| auto dest = params.claimNext(); |
| |
| // Transfer all of the requirements into the destination instance. |
| IGF.Builder.CreateMemCpy(dest, src, |
| IGM.getPointerSize().getValue() * requirements.size(), |
| IGM.getPointerAlignment().getValue()); |
| |
| // TODO: Copy over subscript index values. |
| |
| IGF.Builder.CreateRetVoid(); |
| } |
| return initFn; |
| } |
| |
| llvm::Constant * |
| IRGenModule::getAddrOfKeyPathPattern(KeyPathPattern *pattern, |
| SILLocation diagLoc) { |
| // See if we already emitted this. |
| auto found = KeyPathPatterns.find(pattern); |
| if (found != KeyPathPatterns.end()) |
| return found->second; |
| |
| // Gather type arguments from the root and leaf types of the key path. |
| auto rootTy = pattern->getRootType(); |
| auto valueTy = pattern->getValueType(); |
| |
| // Check for parameterization, whether by subscript indexes or by the generic |
| // environment. If there isn't any, we can instantiate the pattern in-place. |
| bool isInstantiableInPlace = pattern->getNumOperands() == 0 |
| && !pattern->getGenericSignature(); |
| |
| // Collect the required parameters for the keypath's generic environment. |
| SmallVector<GenericRequirement, 4> requirements; |
| |
| GenericEnvironment *genericEnv = nullptr; |
| if (auto sig = pattern->getGenericSignature()) { |
| genericEnv = sig->createGenericEnvironment(*getSwiftModule()); |
| enumerateGenericSignatureRequirements(pattern->getGenericSignature(), |
| [&](GenericRequirement reqt) { requirements.push_back(reqt); }); |
| } |
| |
| /// Generate a metadata accessor that produces metadata for the given type |
| /// using arguments from the generic context of the key path. |
| auto emitMetadataGenerator = [&](CanType type) -> llvm::Function * { |
| // TODO: Use the standard metadata accessor when there are no arguments |
| // and the metadata accessor is defined. |
| |
| // Build a stub that loads the necessary bindings from the key path's |
| // argument buffer then fetches the metadata. |
| auto fnTy = llvm::FunctionType::get(TypeMetadataPtrTy, |
| {Int8PtrTy}, /*vararg*/ false); |
| auto accessorThunk = llvm::Function::Create(fnTy, |
| llvm::GlobalValue::PrivateLinkage, |
| "keypath_get_type", getModule()); |
| accessorThunk->setAttributes(constructInitialAttributes()); |
| { |
| IRGenFunction IGF(*this, accessorThunk); |
| if (DebugInfo) |
| DebugInfo->emitArtificialFunction(IGF, accessorThunk); |
| |
| if (type->hasTypeParameter()) { |
| auto bindingsBufPtr = IGF.collectParameters().claimNext(); |
| |
| bindFromGenericRequirementsBuffer(IGF, requirements, |
| Address(bindingsBufPtr, getPointerAlignment()), |
| [&](CanType t) { |
| if (!genericEnv) |
| return t; |
| return genericEnv->mapTypeIntoContext(t)->getCanonicalType(); |
| }); |
| |
| type = genericEnv->mapTypeIntoContext(type)->getCanonicalType(); |
| } |
| auto ret = IGF.emitTypeMetadataRef(type); |
| IGF.Builder.CreateRet(ret); |
| } |
| return accessorThunk; |
| }; |
| |
| // Start building the key path pattern. |
| ConstantInitBuilder builder(*this); |
| ConstantStructBuilder fields = builder.beginStruct(); |
| fields.setPacked(true); |
| // Add a zero-initialized header we can use for lazy initialization. |
| fields.add(llvm::ConstantInt::get(SizeTy, 0)); |
| |
| #ifndef NDEBUG |
| auto startOfObject = fields.getNextOffsetFromGlobal(); |
| #endif |
| |
| // Store references to metadata generator functions to generate the metadata |
| // for the root and leaf. These sit in the "isa" and object header parts of |
| // the final object. |
| fields.add(emitMetadataGenerator(rootTy)); |
| fields.add(emitMetadataGenerator(valueTy)); |
| |
| // TODO: 32-bit heap object header still has an extra word |
| if (SizeTy == Int32Ty) { |
| fields.addInt32(0); |
| } |
| |
| #ifndef NDEBUG |
| auto endOfObjectHeader = fields.getNextOffsetFromGlobal(); |
| unsigned expectedObjectHeaderSize; |
| if (SizeTy == Int64Ty) |
| expectedObjectHeaderSize = SWIFT_ABI_HEAP_OBJECT_HEADER_SIZE_64; |
| else if (SizeTy == Int32Ty) |
| expectedObjectHeaderSize = SWIFT_ABI_HEAP_OBJECT_HEADER_SIZE_32; |
| else |
| llvm_unreachable("unexpected pointer size"); |
| assert((endOfObjectHeader - startOfObject).getValue() |
| == expectedObjectHeaderSize |
| && "key path pattern header size doesn't match heap object header size"); |
| #endif |
| |
| // Add a pointer to the ObjC KVC compatibility string, if there is one, or |
| // null otherwise. |
| llvm::Constant *objcString; |
| if (!pattern->getObjCString().empty()) { |
| objcString = getAddrOfGlobalString(pattern->getObjCString()); |
| } else { |
| objcString = llvm::ConstantPointerNull::get(Int8PtrTy); |
| } |
| fields.add(objcString); |
| |
| // Leave a placeholder for the buffer header, since we need to know the full |
| // buffer size to fill it in. |
| auto headerPlaceholder = fields.addPlaceholderWithSize(Int32Ty); |
| fields.addAlignmentPadding(getPointerAlignment()); |
| |
| auto startOfKeyPathBuffer = fields.getNextOffsetFromGlobal(); |
| |
| // Build out the components. |
| auto baseTy = rootTy; |
| |
| auto assertPointerAlignment = [&]{ |
| assert(fields.getNextOffsetFromGlobal() % getPointerAlignment() == Size(0) |
| && "must be pointer-aligned here"); |
| }; |
| |
| for (unsigned i : indices(pattern->getComponents())) { |
| assertPointerAlignment(); |
| SILType loweredBaseTy; |
| Lowering::GenericContextScope scope(getSILTypes(), |
| pattern->getGenericSignature()); |
| loweredBaseTy = getLoweredType(AbstractionPattern::getOpaque(), |
| baseTy->getWithoutSpecifierType()); |
| auto &component = pattern->getComponents()[i]; |
| switch (auto kind = component.getKind()) { |
| case KeyPathPatternComponent::Kind::StoredProperty: { |
| auto property = cast<VarDecl>(component.getStoredPropertyDecl()); |
| |
| auto addFixedOffset = [&](bool isStruct, llvm::Constant *offset) { |
| if (auto offsetInt = dyn_cast_or_null<llvm::ConstantInt>(offset)) { |
| auto offsetValue = offsetInt->getValue().getZExtValue(); |
| if (KeyPathComponentHeader::offsetCanBeInline(offsetValue)) { |
| auto header = isStruct |
| ? KeyPathComponentHeader::forStructComponentWithInlineOffset(offsetValue) |
| : KeyPathComponentHeader::forClassComponentWithInlineOffset(offsetValue); |
| fields.addInt32(header.getData()); |
| return; |
| } |
| } |
| auto header = isStruct |
| ? KeyPathComponentHeader::forStructComponentWithOutOfLineOffset() |
| : KeyPathComponentHeader::forClassComponentWithOutOfLineOffset(); |
| fields.addInt32(header.getData()); |
| fields.add(llvm::ConstantExpr::getTruncOrBitCast(offset, Int32Ty)); |
| }; |
| |
| // For a struct stored property, we may know the fixed offset of the field, |
| // or we may need to fetch it out of the type's metadata at instantiation |
| // time. |
| if (loweredBaseTy.getStructOrBoundGenericStruct()) { |
| if (auto offset = emitPhysicalStructMemberFixedOffset(*this, |
| loweredBaseTy, |
| property)) { |
| // We have a known constant fixed offset. |
| addFixedOffset(/*struct*/ true, offset); |
| break; |
| } |
| |
| // If the offset isn't fixed, try instead to get the field offset out |
| // of the type metadata at instantiation time. |
| auto fieldOffset = emitPhysicalStructMemberOffsetOfFieldOffset( |
| *this, loweredBaseTy, property); |
| auto header = KeyPathComponentHeader::forStructComponentWithUnresolvedFieldOffset(); |
| fields.addInt32(header.getData()); |
| fields.add(llvm::ConstantExpr::getTruncOrBitCast(fieldOffset, |
| Int32Ty)); |
| break; |
| } |
| |
| // For a class, we may know the fixed offset of a field at compile time, |
| // or we may need to fetch it at instantiation time. Depending on the |
| // ObjC-ness and resilience of the class hierarchy, there might be a few |
| // different ways we need to go about this. |
| if (loweredBaseTy.getClassOrBoundGenericClass()) { |
| switch (getClassFieldAccess(*this, loweredBaseTy, property)) { |
| case FieldAccess::ConstantDirect: { |
| // Known constant fixed offset. |
| auto offset = tryEmitConstantClassFragilePhysicalMemberOffset(*this, |
| loweredBaseTy, |
| property); |
| assert(offset && "no constant offset for ConstantDirect field?!"); |
| addFixedOffset(/*struct*/ false, offset); |
| break; |
| } |
| case FieldAccess::NonConstantDirect: { |
| // A constant offset that's determined at class realization time. |
| // We have to load the offset from a global ivar. |
| auto header = |
| KeyPathComponentHeader::forClassComponentWithUnresolvedIndirectOffset(); |
| fields.addInt32(header.getData()); |
| fields.addAlignmentPadding(getPointerAlignment()); |
| auto offsetVar = getAddrOfFieldOffset(property, /*indirect*/ false, |
| NotForDefinition); |
| fields.add(cast<llvm::Constant>(offsetVar.getAddress())); |
| break; |
| } |
| case FieldAccess::ConstantIndirect: { |
| // An offset that depends on the instance's generic parameterization, |
| // but whose field offset is at a known vtable offset. |
| auto header = |
| KeyPathComponentHeader::forClassComponentWithUnresolvedFieldOffset(); |
| fields.addInt32(header.getData()); |
| auto fieldOffset = |
| getClassFieldOffset(*this, loweredBaseTy.getClassOrBoundGenericClass(), |
| property); |
| fields.addInt32(fieldOffset.getValue()); |
| break; |
| } |
| case FieldAccess::NonConstantIndirect: |
| // An offset that depends on the instance's generic parameterization, |
| // whose vtable offset is also unknown. |
| // TODO: This doesn't happen until class resilience is enabled. |
| llvm_unreachable("not implemented"); |
| } |
| break; |
| } |
| llvm_unreachable("not struct or class"); |
| } |
| case KeyPathPatternComponent::Kind::GettableProperty: |
| case KeyPathPatternComponent::Kind::SettableProperty: { |
| // Encode the settability. |
| bool settable = kind == KeyPathPatternComponent::Kind::SettableProperty; |
| KeyPathComponentHeader::ComputedPropertyKind componentKind; |
| if (settable) { |
| componentKind = component.isComputedSettablePropertyMutating() |
| ? KeyPathComponentHeader::SettableMutating |
| : KeyPathComponentHeader::SettableNonmutating; |
| } else { |
| componentKind = KeyPathComponentHeader::GetOnly; |
| } |
| |
| // Lower the id reference. |
| auto id = component.getComputedPropertyId(); |
| KeyPathComponentHeader::ComputedPropertyIDKind idKind; |
| llvm::Constant *idValue; |
| bool idResolved; |
| switch (id.getKind()) { |
| case KeyPathPatternComponent::ComputedPropertyId::Function: |
| idKind = KeyPathComponentHeader::Pointer; |
| idValue = getAddrOfSILFunction(id.getFunction(), NotForDefinition); |
| idResolved = true; |
| break; |
| case KeyPathPatternComponent::ComputedPropertyId::DeclRef: { |
| auto declRef = id.getDeclRef(); |
| |
| // Foreign method refs identify using a selector |
| // reference, which is doubly-indirected and filled in with a unique |
| // pointer by dyld. |
| if (declRef.isForeign) { |
| assert(ObjCInterop && "foreign keypath component w/o objc interop?!"); |
| idKind = KeyPathComponentHeader::Pointer; |
| idValue = getAddrOfObjCSelectorRef(declRef); |
| idResolved = false; |
| } else { |
| idKind = KeyPathComponentHeader::VTableOffset; |
| auto dc = declRef.getDecl()->getDeclContext(); |
| if (isa<ClassDecl>(dc)) { |
| auto index = getVirtualMethodIndex(*this, declRef); |
| idValue = llvm::ConstantInt::get(SizeTy, index); |
| idResolved = true; |
| } else if (auto methodProto = dyn_cast<ProtocolDecl>(dc)) { |
| auto &protoInfo = getProtocolInfo(methodProto); |
| auto index = protoInfo.getFunctionIndex( |
| cast<AbstractFunctionDecl>(declRef.getDecl())); |
| idValue = llvm::ConstantInt::get(SizeTy, -index.getValue()); |
| idResolved = true; |
| } else { |
| llvm_unreachable("neither a class nor protocol dynamic method?"); |
| } |
| } |
| break; |
| } |
| case KeyPathPatternComponent::ComputedPropertyId::Property: |
| // Use the index of the stored property within the aggregate to key |
| // the property. |
| auto property = id.getProperty(); |
| idKind = KeyPathComponentHeader::StoredPropertyIndex; |
| if (baseTy->getStructOrBoundGenericStruct()) { |
| idResolved = true; |
| idValue = llvm::ConstantInt::get(SizeTy, |
| getPhysicalStructFieldIndex(*this, |
| SILType::getPrimitiveAddressType(baseTy), property)); |
| } else if (baseTy->getClassOrBoundGenericClass()) { |
| // TODO: This field index would require runtime resolution with Swift |
| // native class resilience. We never directly access ObjC-imported |
| // ivars so we can disregard ObjC ivar resilience for this computation |
| // and start counting at the Swift native root. |
| switch (getClassFieldAccess(*this, loweredBaseTy, property)) { |
| case FieldAccess::ConstantDirect: |
| case FieldAccess::ConstantIndirect: |
| case FieldAccess::NonConstantDirect: |
| idResolved = true; |
| idValue = llvm::ConstantInt::get(SizeTy, |
| getClassFieldIndex(*this, |
| SILType::getPrimitiveAddressType(baseTy), property)); |
| break; |
| case FieldAccess::NonConstantIndirect: |
| llvm_unreachable("not implemented"); |
| } |
| |
| } else { |
| llvm_unreachable("neither struct nor class"); |
| } |
| break; |
| } |
| |
| auto header = KeyPathComponentHeader::forComputedProperty(componentKind, |
| idKind, !isInstantiableInPlace, idResolved); |
| |
| fields.addInt32(header.getData()); |
| fields.addAlignmentPadding(getPointerAlignment()); |
| fields.add(idValue); |
| |
| if (isInstantiableInPlace) { |
| // No generic arguments or indexes, so we can invoke the |
| // getter/setter as is. |
| fields.add(getAddrOfSILFunction(component.getComputedPropertyGetter(), |
| NotForDefinition)); |
| if (settable) |
| fields.add(getAddrOfSILFunction(component.getComputedPropertySetter(), |
| NotForDefinition)); |
| } else { |
| // If there's generic context (TODO: or subscript indexes), embed as |
| // arguments in the component. Thunk the SIL-level accessors to give the |
| // runtime implementation a polymorphically-callable interface. |
| |
| // Push the accessors, possibly thunked to marshal generic environment. |
| fields.add(getAccessorForComputedComponent(*this, component, Getter, |
| genericEnv, requirements)); |
| if (settable) |
| fields.add(getAccessorForComputedComponent(*this, component, Setter, |
| genericEnv, requirements)); |
| |
| fields.add(getLayoutFunctionForComputedComponent(*this, component, |
| genericEnv, requirements)); |
| |
| // Set up a "witness table" for the component that handles copying, |
| // destroying, equating, and hashing the captured contents of the |
| // component. |
| // If there are only generic parameters, we can use a prefab witness |
| // table from the runtime. |
| // TODO: For subscripts we'd generate functions that dispatch out to |
| // the copy/destroy/equals/hash functionality of the subscript indexes. |
| fields.add(getWitnessTableForComputedComponent(*this, component, |
| genericEnv, requirements)); |
| |
| // Add an initializer function that copies generic arguments out of the |
| // pattern argument buffer into the instantiated object. |
| fields.add(getInitializerForComputedComponent(*this, component, |
| genericEnv, requirements)); |
| } |
| break; |
| } |
| case KeyPathPatternComponent::Kind::OptionalChain: |
| fields.addInt32(KeyPathComponentHeader::forOptionalChain().getData()); |
| break; |
| case KeyPathPatternComponent::Kind::OptionalForce: |
| fields.addInt32(KeyPathComponentHeader::forOptionalForce().getData()); |
| break; |
| case KeyPathPatternComponent::Kind::OptionalWrap: |
| fields.addInt32(KeyPathComponentHeader::forOptionalWrap().getData()); |
| break; |
| } |
| |
| // For all but the last component, we pack in the type of the component. |
| if (i + 1 != pattern->getComponents().size()) { |
| fields.addAlignmentPadding(getPointerAlignment()); |
| fields.add(emitMetadataGenerator(component.getComponentType())); |
| } |
| baseTy = component.getComponentType(); |
| } |
| |
| // Save the total size of the buffer. |
| Size componentSize = fields.getNextOffsetFromGlobal() |
| - startOfKeyPathBuffer; |
| |
| // We now have enough info to build the header. |
| KeyPathBufferHeader header(componentSize.getValue(), isInstantiableInPlace, |
| /*reference prefix*/ false); |
| // Add the header, followed by the components. |
| fields.fillPlaceholder(headerPlaceholder, |
| llvm::ConstantInt::get(Int32Ty, header.getData())); |
| |
| // Create the global variable. |
| // TODO: The pattern could be immutable if |
| // it isn't instantiable in place, and if we made the type metadata accessor |
| // references private, it could go in true-const memory. |
| auto patternVar = fields.finishAndCreateGlobal("keypath", |
| getPointerAlignment(), |
| /*constant*/ false, |
| llvm::GlobalVariable::PrivateLinkage); |
| KeyPathPatterns.insert({pattern, patternVar}); |
| return patternVar; |
| } |
| |
