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fuchsia / third_party / swift / d14f10d8496a8ae290f892fe586ea9a0de1d3c96 / . / lib / Sema / CodeSynthesis.cpp
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//===--- CodeSynthesis.cpp - Type Checking for Declarations ---------------===//
//
// 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 implements semantic analysis for declarations.
//
//===----------------------------------------------------------------------===//
#include "CodeSynthesis.h"
#include "ConstraintSystem.h"
#include "TypeChecker.h"
#include "swift/AST/ASTWalker.h"
#include "swift/AST/Availability.h"
#include "swift/AST/Expr.h"
#include "swift/AST/GenericEnvironment.h"
#include "swift/AST/Initializer.h"
#include "swift/AST/ParameterList.h"
#include "swift/AST/ProtocolConformance.h"
#include "swift/Basic/Defer.h"
#include "swift/ClangImporter/ClangModule.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
using namespace swift;
const bool IsImplicit = true;
/// Insert the specified decl into the DeclContext's member list. If the hint
/// decl is specified, the new decl is inserted next to the hint.
static void addMemberToContextIfNeeded(Decl *D, DeclContext *DC,
Decl *Hint = nullptr) {
if (auto *ntd = dyn_cast<NominalTypeDecl>(DC)) {
ntd->addMember(D, Hint);
} else if (auto *ed = dyn_cast<ExtensionDecl>(DC)) {
ed->addMember(D, Hint);
} else {
assert((isa<AbstractFunctionDecl>(DC) || isa<FileUnit>(DC)) &&
"Unknown declcontext");
}
}
static ParamDecl *getParamDeclAtIndex(FuncDecl *fn, unsigned index) {
return fn->getParameterLists().back()->get(index);
}
static VarDecl *getFirstParamDecl(FuncDecl *fn) {
return getParamDeclAtIndex(fn, 0);
};
static ParamDecl *buildArgument(SourceLoc loc, DeclContext *DC,
StringRef name,
Type type,
Type interfaceType,
VarDecl::Specifier specifier) {
auto &context = DC->getASTContext();
auto *param = new (context) ParamDecl(specifier, SourceLoc(), SourceLoc(),
Identifier(), loc,
context.getIdentifier(name),
type, DC);
param->setImplicit();
param->setInterfaceType(interfaceType);
return param;
}
static Type getTypeOfStorage(AbstractStorageDecl *storage,
bool wantInterfaceType) {
if (auto var = dyn_cast<VarDecl>(storage)) {
auto type = (wantInterfaceType
? var->getInterfaceType()
: var->getType());
return type->getReferenceStorageReferent();
}
auto subscript = cast<SubscriptDecl>(storage);
auto type = subscript->getElementInterfaceType();
if (!wantInterfaceType)
type = storage->getDeclContext()->mapTypeIntoContext(type);
return type;
}
/// Build a parameter list which can forward the formal index parameters of a
/// declaration.
///
/// \param prefix optional arguments to be prefixed onto the index
/// forwarding pattern.
static ParameterList *
buildIndexForwardingParamList(AbstractStorageDecl *storage,
ArrayRef<ParamDecl*> prefix) {
auto &context = storage->getASTContext();
auto subscript = dyn_cast<SubscriptDecl>(storage);
// Fast path: if this isn't a subscript, just use whatever we have.
if (!subscript)
return ParameterList::create(context, prefix);
// Clone the parameter list over for a new decl, so we get new ParamDecls.
auto indices = subscript->getIndices()->clone(context,
ParameterList::Implicit);
if (prefix.empty())
return indices;
// Otherwise, we need to build up a new parameter list.
SmallVector<ParamDecl*, 4> elements;
// Start with the fields we were given, if there are any.
elements.append(prefix.begin(), prefix.end());
elements.append(indices->begin(), indices->end());
return ParameterList::create(context, elements);
}
static FuncDecl *createGetterPrototype(AbstractStorageDecl *storage,
TypeChecker &TC) {
SourceLoc loc = storage->getLoc();
// Create the parameter list for the getter.
SmallVector<ParameterList*, 2> getterParams;
// The implicit 'self' argument if in a type context.
if (storage->getDeclContext()->isTypeContext()) {
ParamDecl *selfDecl;
// For lazy properties, steal the 'self' from the initializer context.
if (storage->getAttrs().hasAttribute<LazyAttr>()) {
auto *varDecl = cast<VarDecl>(storage);
auto *bindingDecl = varDecl->getParentPatternBinding();
auto *bindingInit = cast<PatternBindingInitializer>(
bindingDecl->getPatternEntryForVarDecl(varDecl).getInitContext());
selfDecl = bindingInit->getImplicitSelfDecl();
} else {
selfDecl = ParamDecl::createSelf(loc,
storage->getDeclContext(),
/*isStatic*/false);
}
getterParams.push_back(ParameterList::create(TC.Context, selfDecl));
}
// Add an index-forwarding clause.
getterParams.push_back(buildIndexForwardingParamList(storage, {}));
SourceLoc staticLoc;
if (auto var = dyn_cast<VarDecl>(storage)) {
if (var->isStatic())
staticLoc = var->getLoc();
}
auto storageInterfaceType = getTypeOfStorage(storage, true);
auto getter = FuncDecl::create(
TC.Context, staticLoc, StaticSpellingKind::None, loc, Identifier(), loc,
/*Throws=*/false, /*ThrowsLoc=*/SourceLoc(),
/*AccessorKeywordLoc=*/SourceLoc(), /*GenericParams=*/nullptr,
getterParams, TypeLoc::withoutLoc(storageInterfaceType),
storage->getDeclContext());
getter->setImplicit();
if (storage->isGetterMutating())
getter->setSelfAccessKind(SelfAccessKind::Mutating);
if (storage->isStatic())
getter->setStatic();
return getter;
}
static FuncDecl *createSetterPrototype(AbstractStorageDecl *storage,
ParamDecl *&valueDecl,
TypeChecker &TC) {
SourceLoc loc = storage->getLoc();
// Create the parameter list for the setter.
SmallVector<ParameterList*, 2> params;
bool isStatic = storage->isStatic();
bool isMutating = storage->isSetterMutating();
// The implicit 'self' argument if in a type context.
if (storage->getDeclContext()->isTypeContext()) {
params.push_back(ParameterList::createSelf(loc,
storage->getDeclContext(),
/*isStatic*/isStatic,
/*isInOut*/isMutating));
}
// Add a "(value : T, indices...)" argument list.
auto storageType = getTypeOfStorage(storage, false);
auto storageInterfaceType = getTypeOfStorage(storage, true);
valueDecl = buildArgument(storage->getLoc(),
storage->getDeclContext(), "value",
storageType,
storageInterfaceType,
VarDecl::Specifier::Owned);
params.push_back(buildIndexForwardingParamList(storage, valueDecl));
Type setterRetTy = TupleType::getEmpty(TC.Context);
FuncDecl *setter = FuncDecl::create(
TC.Context, /*StaticLoc=*/SourceLoc(), StaticSpellingKind::None, loc,
Identifier(), loc, /*Throws=*/false, /*ThrowsLoc=*/SourceLoc(),
/*AccessorKeywordLoc=*/SourceLoc(), /*GenericParams=*/nullptr,
params, TypeLoc::withoutLoc(setterRetTy),
storage->getDeclContext());
setter->setImplicit();
if (isMutating)
setter->setSelfAccessKind(SelfAccessKind::Mutating);
if (isStatic)
setter->setStatic();
return setter;
}
// True if the storage is dynamic or imported from Objective-C. In these cases,
// we need to emit a static materializeForSet thunk that dynamically dispatches
// to 'get' and 'set', rather than the normal dynamically dispatched
// materializeForSet that peer dispatches to 'get' and 'set'.
static bool needsDynamicMaterializeForSet(AbstractStorageDecl *storage) {
return storage->isDynamic() || storage->hasClangNode();
}
// True if a generated accessor needs to be registered as an external decl.
bool needsToBeRegisteredAsExternalDecl(AbstractStorageDecl *storage) {
// Either the storage itself was imported from Clang...
if (storage->hasClangNode())
return true;
// ...or it was synthesized into an imported context.
const DeclContext *dc = storage->getDeclContext();
return isa<ClangModuleUnit>(dc->getModuleScopeContext());
}
/// Mark the accessor as transparent if we can.
///
/// If the storage is inside a fixed-layout nominal type, we can mark the
/// accessor as transparent, since in this case we just want it for abstraction
/// purposes (i.e., to make access to the variable uniform and to be able to
/// put the getter in a vtable).
///
/// If the storage is for a global stored property or a stored property of a
/// resilient type, we are synthesizing accessors to present a resilient
/// interface to the storage and they should not be transparent.
static void maybeMarkTransparent(FuncDecl *accessor,
AbstractStorageDecl *storage,
TypeChecker &TC) {
auto *DC = storage->getDeclContext();
auto *nominalDecl = DC->getAsNominalTypeOrNominalTypeExtensionContext();
// Global variable accessors are not @_transparent.
if (!nominalDecl)
return;
// Accessors for stored properties of resilient types are not
// @_transparent.
if (!nominalDecl->hasFixedLayout())
return;
// Accessors for protocol storage requirements are never @_transparent
// since they do not have bodies.
//
// FIXME: Revisit this if we ever get 'real' default implementations.
if (isa<ProtocolDecl>(nominalDecl))
return;
// Accessors for classes with @objc ancestry are not @_transparent,
// since they use a field offset variable which is not exported.
if (auto *classDecl = dyn_cast<ClassDecl>(nominalDecl))
if (classDecl->checkObjCAncestry() != ObjCClassKind::NonObjC)
return;
accessor->getAttrs().add(new (TC.Context) TransparentAttr(IsImplicit));
}
static FuncDecl *createMaterializeForSetPrototype(AbstractStorageDecl *storage,
FuncDecl *setter,
TypeChecker &TC) {
auto &ctx = storage->getASTContext();
SourceLoc loc = storage->getLoc();
// Create the parameter list:
SmallVector<ParameterList*, 2> params;
// - The implicit 'self' argument if in a type context.
auto DC = storage->getDeclContext();
if (DC->isTypeContext())
params.push_back(ParameterList::createSelf(loc, DC, /*isStatic*/false));
// - The buffer parameter, (buffer: Builtin.RawPointer,
// inout storage: Builtin.UnsafeValueBuffer,
// indices...).
ParamDecl *bufferElements[] = {
buildArgument(loc, DC, "buffer",
ctx.TheRawPointerType,
ctx.TheRawPointerType,
VarDecl::Specifier::Owned),
buildArgument(loc, DC, "callbackStorage",
ctx.TheUnsafeValueBufferType,
ctx.TheUnsafeValueBufferType,
VarDecl::Specifier::InOut)
};
params.push_back(buildIndexForwardingParamList(storage, bufferElements));
// The accessor returns (temporary: Builtin.RawPointer,
// callback: Builtin.RawPointer),
// where the first pointer is the materialized address and the
// second is the address of an optional callback.
TupleTypeElt retElts[] = {
{ ctx.TheRawPointerType },
{ OptionalType::get(ctx.TheRawPointerType) },
};
Type retTy = TupleType::get(retElts, ctx);
// Accessors of generic subscripts get a copy of the subscript's
// generic parameter list, because they're not nested inside the
// subscript.
GenericParamList *genericParams = nullptr;
if (auto *subscript = dyn_cast<SubscriptDecl>(storage))
genericParams = subscript->getGenericParams();
auto *materializeForSet = FuncDecl::create(
ctx, /*StaticLoc=*/SourceLoc(), StaticSpellingKind::None, loc,
Identifier(), loc, /*Throws=*/false, /*ThrowsLoc=*/SourceLoc(),
/*AccessorKeywordLoc=*/SourceLoc(),
(genericParams
? genericParams->clone(DC)
: nullptr),
params, TypeLoc::withoutLoc(retTy), DC);
materializeForSet->setImplicit();
// Open-code the setMutating() calculation since we might run before
// the setter has been type checked.
Type contextTy = DC->getDeclaredInterfaceType();
if (contextTy && !contextTy->hasReferenceSemantics() &&
!setter->getAttrs().hasAttribute<NonMutatingAttr>() &&
storage->isSetterMutating())
materializeForSet->setSelfAccessKind(SelfAccessKind::Mutating);
materializeForSet->setStatic(storage->isStatic());
// materializeForSet is final if the storage is.
if (storage->isFinal())
makeFinal(ctx, materializeForSet);
// If the storage is dynamic or ObjC-native, we can't add a dynamically-
// dispatched method entry for materializeForSet, so force it to be
// statically dispatched. ("final" would be inappropriate because the
// property can still be overridden.)
if (needsDynamicMaterializeForSet(storage))
materializeForSet->setForcedStaticDispatch(true);
// Make sure materializeForSet is available enough to access
// the storage (and its getters/setters if it has them).
SmallVector<const Decl *, 2> asAvailableAs;
asAvailableAs.push_back(storage);
if (FuncDecl *getter = storage->getGetter()) {
asAvailableAs.push_back(getter);
}
if (FuncDecl *setter = storage->getSetter()) {
asAvailableAs.push_back(setter);
}
maybeMarkTransparent(materializeForSet, storage, TC);
AvailabilityInference::applyInferredAvailableAttrs(materializeForSet,
asAvailableAs, ctx);
// If the property came from ObjC, we need to register this as an external
// definition to be compiled.
if (needsToBeRegisteredAsExternalDecl(storage))
TC.Context.addExternalDecl(materializeForSet);
TC.DeclsToFinalize.insert(materializeForSet);
return materializeForSet;
}
static void convertStoredVarInProtocolToComputed(VarDecl *VD, TypeChecker &TC) {
auto *Get = createGetterPrototype(VD, TC);
// Okay, we have both the getter and setter. Set them in VD.
VD->makeComputed(SourceLoc(), Get, nullptr, nullptr, SourceLoc());
// We've added some members to our containing class, add them to the members
// list.
addMemberToContextIfNeeded(Get, VD->getDeclContext(), VD);
}
/// Build an expression that evaluates the specified parameter list as a tuple
/// or paren expr, suitable for use in an applyexpr.
///
/// NOTE: This returns null if a varargs parameter exists in the list, as it
/// cannot be forwarded correctly yet.
///
static Expr *buildArgumentForwardingExpr(ArrayRef<ParamDecl*> params,
ASTContext &ctx) {
SmallVector<Identifier, 4> labels;
SmallVector<SourceLoc, 4> labelLocs;
SmallVector<Expr *, 4> args;
for (auto param : params) {
// We cannot express how to forward variadic parameters yet.
if (param->isVariadic())
return nullptr;
Expr *ref = new (ctx) DeclRefExpr(param, DeclNameLoc(), /*implicit*/ true);
if (param->isInOut())
ref = new (ctx) InOutExpr(SourceLoc(), ref, Type(), /*isImplicit=*/true);
args.push_back(ref);
labels.push_back(param->getArgumentName());
labelLocs.push_back(SourceLoc());
}
// A single unlabeled value is not a tuple.
if (args.size() == 1 && labels[0].empty()) {
return new (ctx) ParenExpr(SourceLoc(), args[0], SourceLoc(),
/*hasTrailingClosure=*/false);
}
return TupleExpr::create(ctx, SourceLoc(), args, labels, labelLocs,
SourceLoc(), false, IsImplicit);
}
/// Build a reference to the subscript index variables for this subscript
/// accessor.
static Expr *buildSubscriptIndexReference(ASTContext &ctx, FuncDecl *accessor) {
// Pull out the body parameters, which we should have cloned
// previously to be forwardable. Drop the initial buffer/value
// parameter in accessors that have one.
auto params = accessor->getParameterLists().back()->getArray();
auto accessorKind = accessor->getAccessorKind();
// Ignore the value/buffer parameter.
if (accessorKind != AccessorKind::IsGetter)
params = params.slice(1);
// Ignore the materializeForSet callback storage parameter.
if (accessorKind == AccessorKind::IsMaterializeForSet)
params = params.slice(1);
// Okay, everything else should be forwarded, build the expression.
auto result = buildArgumentForwardingExpr(params, ctx);
assert(result && "FIXME: Cannot forward varargs");
return result;
}
enum class SelfAccessorKind {
/// We're building a derived accessor on top of whatever this
/// class provides.
Peer,
/// We're building a setter or something around an underlying
/// implementation, which might be storage or inherited from a
/// superclass.
Super,
};
static Expr *buildSelfReference(VarDecl *selfDecl,
SelfAccessorKind selfAccessorKind,
TypeChecker &TC) {
switch (selfAccessorKind) {
case SelfAccessorKind::Peer:
return new (TC.Context) DeclRefExpr(selfDecl, DeclNameLoc(), IsImplicit);
case SelfAccessorKind::Super:
return new (TC.Context) SuperRefExpr(selfDecl, SourceLoc(), IsImplicit);
}
llvm_unreachable("bad self access kind");
}
namespace {
/// A simple helper interface for buildStorageReference.
class StorageReferenceContext {
StorageReferenceContext(const StorageReferenceContext &) = delete;
public:
StorageReferenceContext() = default;
virtual ~StorageReferenceContext() = default;
/// Returns the declaration of the entity to use as the base of
/// the access, or nil if no base is required.
virtual VarDecl *getSelfDecl() const = 0;
/// Returns an expression producing the index value, assuming that
/// the storage is a subscript declaration.
virtual Expr *getIndexRefExpr(ASTContext &ctx,
SubscriptDecl *subscript) const = 0;
};
/// A reference to storage from within an accessor.
class AccessorStorageReferenceContext : public StorageReferenceContext {
FuncDecl *Accessor;
public:
AccessorStorageReferenceContext(FuncDecl *accessor) : Accessor(accessor) {}
~AccessorStorageReferenceContext() override = default;
VarDecl *getSelfDecl() const override {
return Accessor->getImplicitSelfDecl();
}
Expr *getIndexRefExpr(ASTContext &ctx,
SubscriptDecl *subscript) const override {
return buildSubscriptIndexReference(ctx, Accessor);
}
};
} // end anonymous namespace
/// Build an l-value for the storage of a declaration.
static Expr *buildStorageReference(
const StorageReferenceContext &referenceContext,
AbstractStorageDecl *storage,
AccessSemantics semantics,
SelfAccessorKind selfAccessorKind,
TypeChecker &TC) {
ASTContext &ctx = TC.Context;
VarDecl *selfDecl = referenceContext.getSelfDecl();
if (!selfDecl) {
return new (ctx) DeclRefExpr(storage, DeclNameLoc(), IsImplicit, semantics);
}
// If we should use a super access if applicable, and we have an
// overridden decl, then use ordinary access to it.
if (selfAccessorKind == SelfAccessorKind::Super) {
if (auto overridden = storage->getOverriddenDecl()) {
storage = overridden;
semantics = AccessSemantics::Ordinary;
} else {
selfAccessorKind = SelfAccessorKind::Peer;
}
}
Expr *selfDRE = buildSelfReference(selfDecl, selfAccessorKind, TC);
if (auto subscript = dyn_cast<SubscriptDecl>(storage)) {
Expr *indices = referenceContext.getIndexRefExpr(ctx, subscript);
return SubscriptExpr::create(ctx, selfDRE, indices, storage,
IsImplicit, semantics);
}
// This is a potentially polymorphic access, which is unnecessary;
// however, it shouldn't be problematic because any overrides
// should also redefine materializeForSet.
return new (ctx) MemberRefExpr(selfDRE, SourceLoc(), storage,
DeclNameLoc(), IsImplicit, semantics);
}
static Expr *buildStorageReference(FuncDecl *accessor,
AbstractStorageDecl *storage,
AccessSemantics semantics,
SelfAccessorKind selfAccessorKind,
TypeChecker &TC) {
return buildStorageReference(AccessorStorageReferenceContext(accessor),
storage, semantics, selfAccessorKind, TC);
}
/// Load the value of VD. If VD is an @override of another value, we call the
/// superclass getter. Otherwise, we do a direct load of the value.
static Expr *createPropertyLoadOrCallSuperclassGetter(FuncDecl *accessor,
AbstractStorageDecl *storage,
TypeChecker &TC) {
return buildStorageReference(accessor, storage,
AccessSemantics::DirectToStorage,
SelfAccessorKind::Super, TC);
}
/// Look up the NSCopying protocol from the Foundation module, if present.
/// Otherwise return null.
static ProtocolDecl *getNSCopyingProtocol(TypeChecker &TC,
DeclContext *DC) {
ASTContext &ctx = TC.Context;
auto foundation = ctx.getLoadedModule(ctx.Id_Foundation);
if (!foundation)
return nullptr;
SmallVector<ValueDecl *, 2> results;
DC->lookupQualified(ModuleType::get(foundation),
ctx.getSwiftId(KnownFoundationEntity::NSCopying),
NL_QualifiedDefault | NL_KnownNonCascadingDependency,
/*typeResolver=*/nullptr,
results);
if (results.size() != 1)
return nullptr;
return dyn_cast<ProtocolDecl>(results.front());
}
/// Synthesize the code to store 'Val' to 'VD', given that VD has an @NSCopying
/// attribute on it. We know that VD is a stored property in a class, so we
/// just need to generate something like "self.property = val.copy(zone: nil)"
/// here. This does some type checking to validate that the call will succeed.
static Expr *synthesizeCopyWithZoneCall(Expr *Val, VarDecl *VD,
TypeChecker &TC) {
auto &Ctx = TC.Context;
// We support @NSCopying on class types (which conform to NSCopying),
// protocols which conform, and option types thereof.
Type UnderlyingType = VD->getType()->getReferenceStorageReferent();
bool isOptional = false;
if (Type optionalEltTy = UnderlyingType->getAnyOptionalObjectType()) {
UnderlyingType = optionalEltTy;
isOptional = true;
}
// The element type must conform to NSCopying. If not, emit an error and just
// recovery by synthesizing without the copy call.
auto *CopyingProto = getNSCopyingProtocol(TC, VD->getDeclContext());
if (!CopyingProto || !TC.conformsToProtocol(UnderlyingType, CopyingProto,
VD->getDeclContext(), None)) {
TC.diagnose(VD->getLoc(), diag::nscopying_doesnt_conform);
return Val;
}
// If we have an optional type, we have to "?" the incoming value to only
// evaluate the subexpression if the incoming value is non-null.
if (isOptional)
Val = new (Ctx) BindOptionalExpr(Val, SourceLoc(), 0);
// Generate:
// (force_value_expr type='<null>'
// (call_expr type='<null>'
// (unresolved_dot_expr type='<null>' field 'copy'
// "Val")
// (paren_expr type='<null>'
// (nil_literal_expr type='<null>'))))
auto UDE = new (Ctx) UnresolvedDotExpr(Val, SourceLoc(),
Ctx.getIdentifier("copy"),
DeclNameLoc(), /*implicit*/true);
Expr *Nil = new (Ctx) NilLiteralExpr(SourceLoc(), /*implicit*/true);
//- (id)copyWithZone:(NSZone *)zone;
Expr *Call = CallExpr::createImplicit(Ctx, UDE, { Nil }, { Ctx.Id_with });
TypeLoc ResultTy;
ResultTy.setType(VD->getType(), true);
// If we're working with non-optional types, we're forcing the cast.
if (!isOptional) {
Call = new (Ctx) ForcedCheckedCastExpr(Call, SourceLoc(), SourceLoc(),
TypeLoc::withoutLoc(UnderlyingType));
Call->setImplicit();
return Call;
}
// We're working with optional types, so perform a conditional checked
// downcast.
Call = new (Ctx) ConditionalCheckedCastExpr(Call, SourceLoc(), SourceLoc(),
TypeLoc::withoutLoc(UnderlyingType));
Call->setImplicit();
// Use OptionalEvaluationExpr to evaluate the "?".
return new (Ctx) OptionalEvaluationExpr(Call);
}
/// In a synthesized accessor body, store 'value' to the appropriate element.
///
/// If the property is an override, we call the superclass setter.
/// Otherwise, we do a direct store of the value.
static void createPropertyStoreOrCallSuperclassSetter(FuncDecl *accessor,
Expr *value,
AbstractStorageDecl *storage,
SmallVectorImpl<ASTNode> &body,
TypeChecker &TC) {
// If the storage is an @NSCopying property, then we store the
// result of a copyWithZone call on the value, not the value itself.
if (auto property = dyn_cast<VarDecl>(storage)) {
if (property->getAttrs().hasAttribute<NSCopyingAttr>())
value = synthesizeCopyWithZoneCall(value, property, TC);
}
// Create:
// (assign (decl_ref_expr(VD)), decl_ref_expr(value))
// or:
// (assign (member_ref_expr(decl_ref_expr(self), VD)), decl_ref_expr(value))
Expr *dest = buildStorageReference(accessor, storage,
AccessSemantics::DirectToStorage,
SelfAccessorKind::Super, TC);
body.push_back(new (TC.Context) AssignExpr(dest, SourceLoc(), value,
IsImplicit));
}
/// Synthesize the body of a trivial getter. For a non-member vardecl or one
/// which is not an override of a base class property, it performs a direct
/// storage load. For an override of a base member property, it chains up to
/// super.
static void synthesizeTrivialGetter(FuncDecl *getter,
AbstractStorageDecl *storage,
TypeChecker &TC) {
auto &ctx = TC.Context;
Expr *result = createPropertyLoadOrCallSuperclassGetter(getter, storage, TC);
ASTNode returnStmt = new (ctx) ReturnStmt(SourceLoc(), result, IsImplicit);
SourceLoc loc = storage->getLoc();
getter->setBody(BraceStmt::create(ctx, loc, returnStmt, loc, true));
// Record the getter as an override, which can happen with addressors.
if (auto *baseASD = storage->getOverriddenDecl())
if (baseASD->isAccessibleFrom(storage->getDeclContext()))
getter->setOverriddenDecl(baseASD->getGetter());
// Register the accessor as an external decl if the storage was imported.
if (needsToBeRegisteredAsExternalDecl(storage))
TC.Context.addExternalDecl(getter);
TC.DeclsToFinalize.insert(getter);
}
/// Synthesize the body of a trivial setter.
static void synthesizeTrivialSetter(FuncDecl *setter,
AbstractStorageDecl *storage,
VarDecl *valueVar,
TypeChecker &TC) {
auto &ctx = TC.Context;
SourceLoc loc = storage->getLoc();
auto *valueDRE = new (ctx) DeclRefExpr(valueVar, DeclNameLoc(), IsImplicit);
SmallVector<ASTNode, 1> setterBody;
createPropertyStoreOrCallSuperclassSetter(setter, valueDRE, storage,
setterBody, TC);
setter->setBody(BraceStmt::create(ctx, loc, setterBody, loc, true));
// Record the setter as an override, which can happen with addressors.
if (auto *baseASD = storage->getOverriddenDecl()) {
auto *baseSetter = baseASD->getSetter();
if (baseSetter != nullptr &&
baseASD->isSetterAccessibleFrom(storage->getDeclContext())) {
setter->setOverriddenDecl(baseSetter);
}
}
// Register the accessor as an external decl if the storage was imported.
if (needsToBeRegisteredAsExternalDecl(storage))
TC.Context.addExternalDecl(setter);
TC.DeclsToFinalize.insert(setter);
}
/// Does a storage decl currently lacking accessor functions require a
/// setter to be synthesized?
static bool doesStorageNeedSetter(AbstractStorageDecl *storage) {
assert(!storage->hasAccessorFunctions());
switch (storage->getStorageKind()) {
// Add a setter to a stored variable unless it's a let.
case AbstractStorageDecl::Stored:
return !cast<VarDecl>(storage)->isLet();
// Addressed storage gets a setter if it has a mutable addressor.
case AbstractStorageDecl::Addressed:
return storage->getMutableAddressor() != nullptr;
// These should already have accessor functions.
case AbstractStorageDecl::StoredWithTrivialAccessors:
case AbstractStorageDecl::StoredWithObservers:
case AbstractStorageDecl::InheritedWithObservers:
case AbstractStorageDecl::AddressedWithTrivialAccessors:
case AbstractStorageDecl::AddressedWithObservers:
case AbstractStorageDecl::ComputedWithMutableAddress:
llvm_unreachable("already has accessor functions");
case AbstractStorageDecl::Computed:
llvm_unreachable("not stored");
}
llvm_unreachable("bad storage kind");
}
/// Add trivial accessors to a Stored or Addressed property.
static void addTrivialAccessorsToStorage(AbstractStorageDecl *storage,
TypeChecker &TC) {
assert(!storage->hasAccessorFunctions() && "already has accessors?");
assert(!storage->getAttrs().hasAttribute<LazyAttr>());
assert(!storage->getAttrs().hasAttribute<NSManagedAttr>());
auto *DC = storage->getDeclContext();
// Create the getter.
auto *getter = createGetterPrototype(storage, TC);
// Create the setter.
FuncDecl *setter = nullptr;
ParamDecl *setterValueParam = nullptr;
if (doesStorageNeedSetter(storage))
setter = createSetterPrototype(storage, setterValueParam, TC);
// Okay, we have both the getter and setter. Set them in VD.
storage->addTrivialAccessors(getter, setter, nullptr);
// Synthesize the body of the getter.
synthesizeTrivialGetter(getter, storage, TC);
maybeMarkTransparent(getter, storage, TC);
if (setter) {
// Synthesize the body of the setter.
synthesizeTrivialSetter(setter, storage, setterValueParam, TC);
maybeMarkTransparent(setter, storage, TC);
}
// We've added some members to our containing context, add them to
// the right list.
addMemberToContextIfNeeded(getter, DC, storage);
if (setter)
addMemberToContextIfNeeded(setter, DC, getter);
maybeAddMaterializeForSet(storage, TC);
}
/// Add a trivial setter and materializeForSet to a
/// ComputedWithMutableAddress storage decl.
void swift::
synthesizeSetterForMutableAddressedStorage(AbstractStorageDecl *storage,
TypeChecker &TC) {
auto setter = storage->getSetter();
assert(setter);
assert(!storage->getSetter()->getBody());
assert(storage->getStorageKind() ==
AbstractStorageDecl::ComputedWithMutableAddress);
// Synthesize the body of the setter.
VarDecl *valueParamDecl = getFirstParamDecl(setter);
synthesizeTrivialSetter(setter, storage, valueParamDecl, TC);
maybeMarkTransparent(setter, storage, TC);
}
/// Add a materializeForSet accessor to the given declaration.
static FuncDecl *addMaterializeForSet(AbstractStorageDecl *storage,
TypeChecker &TC) {
if (TC.Context.getOptionalDecl() == nullptr) {
TC.diagnose(storage->getStartLoc(), diag::optional_intrinsics_not_found);
return nullptr;
}
auto materializeForSet = createMaterializeForSetPrototype(
storage, storage->getSetter(), TC);
addMemberToContextIfNeeded(materializeForSet, storage->getDeclContext(),
storage->getSetter());
storage->setMaterializeForSetFunc(materializeForSet);
// Make sure we record the override.
//
// FIXME: Instead, we should just not call checkOverrides() on
// storage until all accessors are in place.
if (auto *baseASD = storage->getOverriddenDecl()) {
// If the base storage has a private setter, we're not overriding
// materializeForSet either.
auto *baseMFS = baseASD->getMaterializeForSetFunc();
if (baseMFS != nullptr &&
baseASD->isSetterAccessibleFrom(storage->getDeclContext())) {
materializeForSet->setOverriddenDecl(baseMFS);
}
}
return materializeForSet;
}
static void convertNSManagedStoredVarToComputed(VarDecl *VD, TypeChecker &TC) {
assert(VD->getStorageKind() == AbstractStorageDecl::Stored);
// Create the getter.
auto *Get = createGetterPrototype(VD, TC);
// Create the setter.
ParamDecl *SetValueDecl = nullptr;
auto *Set = createSetterPrototype(VD, SetValueDecl, TC);
// Okay, we have both the getter and setter. Set them in VD.
VD->makeComputed(SourceLoc(), Get, Set, nullptr, SourceLoc());
// We've added some members to our containing class/extension, add them to
// the members list.
addMemberToContextIfNeeded(Get, VD->getDeclContext(), VD);
addMemberToContextIfNeeded(Set, VD->getDeclContext(), Get);
maybeAddMaterializeForSet(VD, TC);
}
/// The specified AbstractStorageDecl was just found to satisfy a
/// protocol property requirement. Ensure that it has the full
/// complement of accessors.
void TypeChecker::synthesizeWitnessAccessorsForStorage(
AbstractStorageDecl *requirement,
AbstractStorageDecl *storage) {
// If the decl is stored, convert it to StoredWithTrivialAccessors
// by synthesizing the full set of accessors.
if (!storage->hasAccessorFunctions()) {
// Don't do this if the declaration is lazy or NSManaged.
// This must be a re-entrant attempt to synthesize accessors
// before validateDecl has finished.
if (storage->getAttrs().hasAttribute<LazyAttr>() ||
storage->getAttrs().hasAttribute<NSManagedAttr>())
return;
addTrivialAccessorsToStorage(storage, *this);
}
// @objc protocols don't need a materializeForSet since ObjC doesn't
// have that concept.
bool wantMaterializeForSet =
!requirement->isObjC() && requirement->getSetter();
// If we want wantMaterializeForSet, create it now.
if (wantMaterializeForSet && !storage->getMaterializeForSetFunc())
addMaterializeForSet(storage, *this);
}
/// Given a VarDecl with a willSet: and/or didSet: specifier, synthesize the
/// (trivial) getter and the setter, which calls these.
void swift::synthesizeObservingAccessors(VarDecl *VD, TypeChecker &TC) {
assert(VD->hasObservers());
assert(VD->getGetter() && VD->getSetter() &&
!VD->getGetter()->hasBody() && !VD->getSetter()->hasBody() &&
"willSet/didSet var already has a getter or setter");
auto &Ctx = VD->getASTContext();
SourceLoc Loc = VD->getLoc();
// The getter is always trivial: just perform a (direct!) load of storage, or
// a call of a superclass getter if this is an override.
auto *Get = VD->getGetter();
synthesizeTrivialGetter(Get, VD, TC);
maybeMarkTransparent(Get, VD, TC);
// Okay, the getter is done, create the setter now. Start by finding the
// decls for 'self' and 'value'.
auto *Set = VD->getSetter();
auto *SelfDecl = Set->getImplicitSelfDecl();
VarDecl *ValueDecl = Set->getParameterLists().back()->get(0);
// The setter loads the oldValue, invokes willSet with the incoming value,
// does a direct store, then invokes didSet with the oldValue.
SmallVector<ASTNode, 6> SetterBody;
// If there is a didSet, it will take the old value. Load it into a temporary
// 'let' so we have it for later.
// TODO: check the body of didSet to only do this load (which may call the
// superclass getter) if didSet takes an argument.
VarDecl *OldValue = nullptr;
if (VD->getDidSetFunc()) {
Expr *OldValueExpr
= createPropertyLoadOrCallSuperclassGetter(Set, VD, TC);
OldValue = new (Ctx) VarDecl(/*IsStatic*/false, VarDecl::Specifier::Let,
/*IsCaptureList*/false, SourceLoc(),
Ctx.getIdentifier("tmp"), Type(), Set);
OldValue->setImplicit();
auto *tmpPattern = new (Ctx) NamedPattern(OldValue, /*implicit*/ true);
auto tmpPBD = PatternBindingDecl::create(Ctx, SourceLoc(),
StaticSpellingKind::None,
SourceLoc(),
tmpPattern, OldValueExpr, Set);
tmpPBD->setImplicit();
SetterBody.push_back(tmpPBD);
SetterBody.push_back(OldValue);
}
// Create:
// (call_expr (dot_syntax_call_expr (decl_ref_expr(willSet)),
// (decl_ref_expr(self))),
// (declrefexpr(value)))
// or:
// (call_expr (decl_ref_expr(willSet)), (declrefexpr(value)))
if (auto willSet = VD->getWillSetFunc()) {
Expr *Callee = new (Ctx) DeclRefExpr(willSet, DeclNameLoc(), /*imp*/true);
auto *ValueDRE = new (Ctx) DeclRefExpr(ValueDecl, DeclNameLoc(),
/*imp*/true);
if (SelfDecl) {
auto *SelfDRE = new (Ctx) DeclRefExpr(SelfDecl, DeclNameLoc(),
/*imp*/true);
Callee = new (Ctx) DotSyntaxCallExpr(Callee, SourceLoc(), SelfDRE);
}
SetterBody.push_back(CallExpr::createImplicit(Ctx, Callee, { ValueDRE },
{ Identifier() }));
// Make sure the didSet/willSet accessors are marked final if in a class.
if (!willSet->isFinal() &&
VD->getDeclContext()->getAsClassOrClassExtensionContext())
makeFinal(Ctx, willSet);
}
// Create an assignment into the storage or call to superclass setter.
auto *ValueDRE = new (Ctx) DeclRefExpr(ValueDecl, DeclNameLoc(), true);
createPropertyStoreOrCallSuperclassSetter(Set, ValueDRE, VD, SetterBody, TC);
// Create:
// (call_expr (dot_syntax_call_expr (decl_ref_expr(didSet)),
// (decl_ref_expr(self))),
// (decl_ref_expr(tmp)))
// or:
// (call_expr (decl_ref_expr(didSet)), (decl_ref_expr(tmp)))
if (auto didSet = VD->getDidSetFunc()) {
auto *OldValueExpr = new (Ctx) DeclRefExpr(OldValue, DeclNameLoc(),
/*impl*/true);
Expr *Callee = new (Ctx) DeclRefExpr(didSet, DeclNameLoc(), /*imp*/true);
if (SelfDecl) {
auto *SelfDRE = new (Ctx) DeclRefExpr(SelfDecl, DeclNameLoc(),
/*imp*/true);
Callee = new (Ctx) DotSyntaxCallExpr(Callee, SourceLoc(), SelfDRE);
}
SetterBody.push_back(CallExpr::createImplicit(Ctx, Callee, { OldValueExpr },
{ Identifier() }));
// Make sure the didSet/willSet accessors are marked final if in a class.
if (!didSet->isFinal() &&
VD->getDeclContext()->getAsClassOrClassExtensionContext())
makeFinal(Ctx, didSet);
}
Set->setBody(BraceStmt::create(Ctx, Loc, SetterBody, Loc, true));
}
namespace {
/// This ASTWalker explores an expression tree looking for expressions (which
/// are DeclContext's) and changes their parent DeclContext to NewDC.
class RecontextualizeClosures : public ASTWalker {
DeclContext *NewDC;
public:
RecontextualizeClosures(DeclContext *NewDC) : NewDC(NewDC) {}
std::pair<bool, Expr *> walkToExprPre(Expr *E) override {
// If we find a closure, update its declcontext and do *not* walk into it.
if (auto CE = dyn_cast<AbstractClosureExpr>(E)) {
CE->setParent(NewDC);
return { false, E };
}
if (auto CLE = dyn_cast<CaptureListExpr>(E)) {
// Make sure to recontextualize any decls in the capture list as well.
for (auto &CLE : CLE->getCaptureList()) {
CLE.Var->setDeclContext(NewDC);
CLE.Init->setDeclContext(NewDC);
}
}
return { true, E };
}
/// We don't want to recurse into declarations or statements.
bool walkToDeclPre(Decl *) override { return false; }
std::pair<bool, Stmt*> walkToStmtPre(Stmt *S) override { return {false,S}; }
};
} // end anonymous namespace
/// Synthesize the getter for a lazy property with the specified storage
/// vardecl.
static FuncDecl *completeLazyPropertyGetter(VarDecl *VD, VarDecl *Storage,
TypeChecker &TC) {
auto &Ctx = VD->getASTContext();
// The getter checks the optional, storing the initial value in if nil. The
// specific pattern we generate is:
// get {
// let tmp1 = storage
// if tmp1 {
// return tmp1!
// }
// let tmp2 : Ty = <<initializer expression>>
// storage = tmp2
// return tmp2
// }
auto *Get = VD->getGetter();
SmallVector<ASTNode, 6> Body;
// Load the existing storage and store it into the 'tmp1' temporary.
auto *Tmp1VD = new (Ctx) VarDecl(/*IsStatic*/false, VarDecl::Specifier::Let,
/*IsCaptureList*/false, SourceLoc(),
Ctx.getIdentifier("tmp1"), Type(), Get);
Tmp1VD->setImplicit();
auto *Tmp1PBDPattern = new (Ctx) NamedPattern(Tmp1VD, /*implicit*/true);
auto *Tmp1Init = createPropertyLoadOrCallSuperclassGetter(Get, Storage, TC);
auto *Tmp1PBD = PatternBindingDecl::create(Ctx, /*StaticLoc*/SourceLoc(),
StaticSpellingKind::None,
/*VarLoc*/SourceLoc(),
Tmp1PBDPattern, Tmp1Init, Get);
Body.push_back(Tmp1PBD);
Body.push_back(Tmp1VD);
// Build the early return inside the if.
auto *Tmp1DRE = new (Ctx) DeclRefExpr(Tmp1VD, DeclNameLoc(), /*Implicit*/true,
AccessSemantics::DirectToStorage);
auto *EarlyReturnVal = new (Ctx) ForceValueExpr(Tmp1DRE, SourceLoc());
auto *Return = new (Ctx) ReturnStmt(SourceLoc(), EarlyReturnVal,
/*implicit*/true);
// Build the "if" around the early return.
Tmp1DRE = new (Ctx) DeclRefExpr(Tmp1VD, DeclNameLoc(), /*Implicit*/true,
AccessSemantics::DirectToStorage);
// Call through "hasValue" on the decl ref.
Tmp1DRE->setType(OptionalType::get(VD->getType()));
constraints::ConstraintSystem cs(TC,
VD->getDeclContext(),
constraints::ConstraintSystemOptions());
constraints::Solution solution(cs, constraints::Score());
auto HasValueExpr = solution.convertOptionalToBool(Tmp1DRE, nullptr);
Body.push_back(new (Ctx) IfStmt(SourceLoc(), HasValueExpr, Return,
/*elseloc*/SourceLoc(), /*else*/nullptr,
/*implicit*/ true, Ctx));
auto *Tmp2VD = new (Ctx) VarDecl(/*IsStatic*/false, VarDecl::Specifier::Let,
/*IsCaptureList*/false, SourceLoc(),
Ctx.getIdentifier("tmp2"), VD->getType(),
Get);
Tmp2VD->setImplicit();
// Take the initializer from the PatternBindingDecl for VD.
// TODO: This doesn't work with complicated patterns like:
// lazy var (a,b) = foo()
auto *InitValue = VD->getParentInitializer();
auto PBD = VD->getParentPatternBinding();
unsigned entryIndex = PBD->getPatternEntryIndexForVarDecl(VD);
PBD->setInit(entryIndex, nullptr);
PBD->setInitializerChecked(entryIndex);
// Recontextualize any closure declcontexts nested in the initializer to
// realize that they are in the getter function.
InitValue->walk(RecontextualizeClosures(Get));
Pattern *Tmp2PBDPattern = new (Ctx) NamedPattern(Tmp2VD, /*implicit*/true);
Tmp2PBDPattern = new (Ctx) TypedPattern(Tmp2PBDPattern,
TypeLoc::withoutLoc(VD->getType()),
/*implicit*/true);
auto *Tmp2PBD = PatternBindingDecl::create(Ctx, /*StaticLoc*/SourceLoc(),
StaticSpellingKind::None,
InitValue->getStartLoc(),
Tmp2PBDPattern, InitValue, Get);
Body.push_back(Tmp2PBD);
Body.push_back(Tmp2VD);
// Assign tmp2 into storage.
auto Tmp2DRE = new (Ctx) DeclRefExpr(Tmp2VD, DeclNameLoc(), /*Implicit*/true,
AccessSemantics::DirectToStorage);
createPropertyStoreOrCallSuperclassSetter(Get, Tmp2DRE, Storage, Body, TC);
// Return tmp2.
Tmp2DRE = new (Ctx) DeclRefExpr(Tmp2VD, DeclNameLoc(), /*Implicit*/true,
AccessSemantics::DirectToStorage);
Body.push_back(new (Ctx) ReturnStmt(SourceLoc(), Tmp2DRE, /*implicit*/true));
Get->setBody(BraceStmt::create(Ctx, VD->getLoc(), Body, VD->getLoc(),
/*implicit*/true));
return Get;
}
void TypeChecker::completePropertyBehaviorStorage(VarDecl *VD,
VarDecl *BehaviorStorage,
FuncDecl *DefaultInitStorage,
FuncDecl *ParamInitStorage,
Type SelfTy,
Type StorageTy,
NormalProtocolConformance *BehaviorConformance,
SubstitutionList SelfInterfaceSubs,
SubstitutionList SelfContextSubs) {
assert(BehaviorStorage);
assert((bool)DefaultInitStorage != (bool)ParamInitStorage);
// Substitute the storage type into the conforming context.
auto sig = BehaviorConformance->getProtocol()->getGenericSignatureOfContext();
auto interfaceMap = sig->getSubstitutionMap(SelfInterfaceSubs);
auto SubstStorageInterfaceTy = StorageTy.subst(interfaceMap);
assert(SubstStorageInterfaceTy && "storage type substitution failed?!");
auto contextMap = sig->getSubstitutionMap(SelfContextSubs);
auto SubstStorageContextTy = StorageTy.subst(contextMap);
assert(SubstStorageContextTy && "storage type substitution failed?!");
auto DC = VD->getDeclContext();
SmallString<64> NameBuf = VD->getName().str();
NameBuf += ".storage";
auto StorageName = Context.getIdentifier(NameBuf);
auto storageSpecifier = BehaviorStorage->isSettable(DC)
? VarDecl::Specifier::Var
: VarDecl::Specifier::Let;
auto *Storage = new (Context) VarDecl(
/*IsStatic*/VD->isStatic(), storageSpecifier,
/*IsCaptureList*/false, VD->getLoc(), StorageName, SubstStorageContextTy,
DC);
Storage->setInterfaceType(SubstStorageInterfaceTy);
Storage->setUserAccessible(false);
// Mark the vardecl to be final, implicit, and private. In a class, this
// prevents it from being dynamically dispatched.
if (VD->getDeclContext()->getAsClassOrClassExtensionContext())
makeFinal(Context, Storage);
Storage->setImplicit();
Storage->setAccess(AccessLevel::Private);
Storage->setSetterAccess(AccessLevel::Private);
addMemberToContextIfNeeded(Storage, DC);
// Initialize the storage immediately, if we can.
Expr *InitStorageExpr = nullptr;
auto Method = DefaultInitStorage ? DefaultInitStorage : ParamInitStorage;
auto SpecializeInitStorage = ConcreteDeclRef(Context, Method,
SelfContextSubs);
if (DefaultInitStorage ||
(ParamInitStorage && VD->getParentInitializer())) {
// Build the initializer expression, 'Self.initStorage()', using the
// conformance.
auto SelfTypeRef = TypeExpr::createImplicit(SelfTy, Context);
auto InitStorageRef = new (Context) DeclRefExpr(SpecializeInitStorage,
DeclNameLoc(),
/*implicit*/ true);
auto InitStorageMethodTy = FunctionType::get(Context.TheEmptyTupleType,
SubstStorageContextTy);
auto InitStorageRefTy = FunctionType::get(SelfTypeRef->getType(),
InitStorageMethodTy);
InitStorageRef->setType(InitStorageRefTy);
auto SelfApply = new (Context) DotSyntaxCallExpr(InitStorageRef,
SourceLoc(),
SelfTypeRef);
SelfApply->setImplicit();
SelfApply->setType(InitStorageMethodTy);
SelfApply->setThrows(false);
SmallVector<Expr *, 1> InitStorageArgs;
SmallVector<Identifier, 1> InitStorageArgLabels;
if (ParamInitStorage) {
// Claim the var initializer as the parameter to the `initStorage`
// method.
auto InitValue = VD->getParentInitializer();
auto PBD = VD->getParentPatternBinding();
unsigned entryIndex = PBD->getPatternEntryIndexForVarDecl(VD);
PBD->setInit(entryIndex, nullptr);
PBD->setInitializerChecked(entryIndex);
// Recontextualize any closure declcontexts nested in the initializer to
// realize that they are in the initialization context.
InitValue->walk(RecontextualizeClosures(DC));
// Coerce to the property type.
InitValue = new (Context) CoerceExpr(InitValue, SourceLoc(),
TypeLoc::withoutLoc(SelfContextSubs[1].getReplacement()));
// Type-check the expression.
typeCheckExpression(InitValue, DC);
InitStorageArgs.push_back(InitValue);
InitStorageArgLabels.push_back(Identifier());
}
auto InitStorageExpr = CallExpr::createImplicit(Context,SelfApply,
InitStorageArgs,
InitStorageArgLabels);
InitStorageExpr->setType(SubstStorageContextTy);
InitStorageExpr->setThrows(false);
} else {
// Save the storage property and the initStorage reference for later.
// We'll leave it to DI analysis to insert the initializer call at the
// right place.
auto *Behavior = VD->getMutableBehavior();
Behavior->StorageDecl = Storage;
Behavior->InitStorageDecl = SpecializeInitStorage;
}
// Create the pattern binding decl for the storage decl. This will get
// default initialized using the protocol's initStorage() method.
Pattern *PBDPattern = new (Context) NamedPattern(Storage, /*implicit*/true);
PBDPattern = new (Context) TypedPattern(PBDPattern,
TypeLoc::withoutLoc(SubstStorageContextTy),
/*implicit*/true);
auto *PBD = PatternBindingDecl::create(Context, /*staticloc*/SourceLoc(),
VD->getParentPatternBinding()->getStaticSpelling(),
/*varloc*/VD->getLoc(),
PBDPattern, /*init*/InitStorageExpr,
VD->getDeclContext());
PBD->setImplicit();
PBD->setInitializerChecked(0);
addMemberToContextIfNeeded(PBD, VD->getDeclContext(), VD);
// Add accessors to the storage, since we'll need them to satisfy the
// conformance requirements.
addTrivialAccessorsToStorage(Storage, *this);
// FIXME: Hack to eliminate spurious diagnostics.
if (BehaviorStorage->isStatic() != Storage->isStatic()) return;
// Add the witnesses to the conformance.
recordKnownWitness(BehaviorConformance, BehaviorStorage, Storage);
recordKnownWitness(BehaviorConformance, BehaviorStorage->getGetter(),
Storage->getGetter());
if (BehaviorStorage->isSettable(DC))
recordKnownWitness(BehaviorConformance, BehaviorStorage->getSetter(),
Storage->getSetter());
}
void TypeChecker::completePropertyBehaviorParameter(VarDecl *VD,
FuncDecl *BehaviorParameter,
NormalProtocolConformance *BehaviorConformance,
SubstitutionList SelfInterfaceSubs,
SubstitutionList SelfContextSubs) {
// Create a method to witness the requirement.
auto DC = VD->getDeclContext();
SmallString<64> NameBuf = VD->getName().str();
NameBuf += ".parameter";
auto ParameterBaseName = Context.getIdentifier(NameBuf);
// Substitute the requirement type into the conforming context.
auto sig = BehaviorConformance->getProtocol()->getGenericSignatureOfContext();
auto ParameterTy = BehaviorParameter->getInterfaceType()
->castTo<AnyFunctionType>()
->getResult();
GenericSignature *genericSig = nullptr;
GenericEnvironment *genericEnv = nullptr;
auto interfaceMap = sig->getSubstitutionMap(SelfInterfaceSubs);
auto SubstInterfaceTy = ParameterTy.subst(interfaceMap);
assert(SubstInterfaceTy && "storage type substitution failed?!");
auto contextMap = sig->getSubstitutionMap(SelfContextSubs);
auto SubstBodyResultTy = SubstInterfaceTy->castTo<AnyFunctionType>()
->getResult();
// Add the Self type back to the interface and context types.
if (DC->isTypeContext()) {
if (DC->isGenericContext()) {
genericSig = DC->getGenericSignatureOfContext();
genericEnv = DC->getGenericEnvironmentOfContext();
SubstInterfaceTy = GenericFunctionType::get(genericSig,
DC->getSelfInterfaceType(),
SubstInterfaceTy,
AnyFunctionType::ExtInfo());
} else {
SubstInterfaceTy = FunctionType::get(DC->getSelfInterfaceType(),
SubstInterfaceTy);
}
}
// Borrow the parameters from the requirement declaration.
SmallVector<ParameterList *, 2> ParamLists;
if (DC->isTypeContext()) {
auto self = ParamDecl::createSelf(SourceLoc(), DC);
ParamLists.push_back(ParameterList::create(Context, SourceLoc(),
self, SourceLoc()));
ParamLists.back()->get(0)->setImplicit();
}
assert(BehaviorParameter->getParameterLists().size() == 2);
SmallVector<ParamDecl *, 4> Params;
SmallVector<Identifier, 4> NameComponents;
auto *DeclaredParams = BehaviorParameter->getParameterList(1);
for (unsigned i : indices(*DeclaredParams)) {
auto declaredParam = DeclaredParams->get(i);
auto declaredParamTy = declaredParam->getInterfaceType();
auto interfaceTy = declaredParamTy.subst(interfaceMap);
assert(interfaceTy);
auto contextTy = declaredParamTy.subst(contextMap);
assert(contextTy);
SmallString<64> ParamNameBuf;
{
llvm::raw_svector_ostream names(ParamNameBuf);
names << "%arg." << i;
}
auto param = new (Context) ParamDecl(VarDecl::Specifier::Owned,
SourceLoc(), SourceLoc(),
Identifier(),
SourceLoc(),
Context.getIdentifier(ParamNameBuf),
contextTy, DC);
param->setInterfaceType(interfaceTy);
param->setImplicit();
Params.push_back(param);
NameComponents.push_back(Identifier());
}
ParamLists.push_back(ParameterList::create(Context, Params));
auto *Parameter =
FuncDecl::create(Context, /*StaticLoc=*/SourceLoc(), StaticSpellingKind::None,
/*FuncLoc=*/SourceLoc(),
DeclName(Context, ParameterBaseName, NameComponents),
/*NameLoc=*/SourceLoc(),
/*Throws=*/false, /*ThrowsLoc=*/SourceLoc(),
/*AccessorKeywordLoc=*/SourceLoc(),
/*GenericParams=*/nullptr, ParamLists,
TypeLoc::withoutLoc(SubstBodyResultTy), DC);
Parameter->setInterfaceType(SubstInterfaceTy);
Parameter->setGenericEnvironment(genericEnv);
// Mark the method to be final, implicit, and private. In a class, this
// prevents it from being dynamically dispatched.
if (DC->getAsClassOrClassExtensionContext())
makeFinal(Context, Parameter);
Parameter->setImplicit();
Parameter->setAccess(AccessLevel::Private);
// Recontextualize any closure declcontexts nested in the initializer to
// realize that they are in the parameter function.
assert(VD->getBehavior()->Param);
VD->getBehavior()->Param->walk(RecontextualizeClosures(Parameter));
// Apply and return the closure in the function context.
SmallVector<Expr *, 4> argRefs;
SmallVector<Identifier, 4> argNames;
for (unsigned i : indices(Params)) {
auto param = Params[i];
auto expr = new (Context) DeclRefExpr(param, DeclNameLoc(),
/*implicit*/ true);
argRefs.push_back(expr);
argNames.push_back(DeclaredParams->get(i)->getName());
}
auto apply = CallExpr::createImplicit(Context, VD->getBehavior()->Param,
argRefs, argNames);
// Return the expression value.
auto Ret = new (Context) ReturnStmt(SourceLoc(), apply,
/*implicit*/ true);
auto Body = BraceStmt::create(Context, SourceLoc(), ASTNode(Ret),
SourceLoc(), /*implicit*/ true);
Parameter->setBody(Body);
typeCheckDecl(Parameter, true);
typeCheckDecl(Parameter, false);
addMemberToContextIfNeeded(Parameter, DC);
// Add the witnesses to the conformance.
recordKnownWitness(BehaviorConformance, BehaviorParameter, Parameter);
}
void TypeChecker::completePropertyBehaviorAccessors(VarDecl *VD,
VarDecl *ValueImpl,
Type valueTy,
SubstitutionList SelfInterfaceSubs,
SubstitutionList SelfContextSubs) {
auto selfTy = SelfContextSubs[0].getReplacement();
auto selfIfaceTy = SelfInterfaceSubs[0].getReplacement();
SmallVector<ASTNode, 3> bodyStmts;
auto makeSelfExpr = [&](FuncDecl *fromAccessor,
FuncDecl *toAccessor) -> Expr * {
Expr *selfExpr;
if (VD->getDeclContext()->isTypeContext()) {
ConcreteDeclRef selfRef = fromAccessor->getImplicitSelfDecl();
selfExpr = new (Context) DeclRefExpr(selfRef, DeclNameLoc(),
/*implicit*/ true);
} else {
// self is the empty tuple outside of a type.
selfExpr = TupleExpr::createEmpty(Context, SourceLoc(), SourceLoc(),
/*implicit*/ true);
}
// If forwarding from a nonmutating to a mutating accessor, we need to put
// `self` in a mutable temporary.
auto fromMutating = VD->getDeclContext()->isTypeContext()
&& fromAccessor->getImplicitSelfDecl()->isSettable(fromAccessor);
if (!fromMutating
&& toAccessor->getImplicitSelfDecl()->isSettable(toAccessor)) {
selfExpr->setType(selfTy);
auto var = new (Context) VarDecl(/*IsStatic*/false,
VarDecl::Specifier::Var,
/*IsCaptureList*/false, SourceLoc(),
Context.getIdentifier("tempSelf"),
selfTy, fromAccessor);
var->setInterfaceType(selfIfaceTy);
auto varPat = new (Context) NamedPattern(var);
auto pbd = PatternBindingDecl::create(Context, SourceLoc(),
StaticSpellingKind::None,
SourceLoc(),
varPat, selfExpr,
fromAccessor);
bodyStmts.push_back(var);
bodyStmts.push_back(pbd);
selfExpr = new (Context) DeclRefExpr(var, DeclNameLoc(),
/*implicit*/ true);
}
assert((!fromMutating
|| toAccessor->getImplicitSelfDecl()->isSettable(toAccessor))
&& "can't forward from mutating to nonmutating");
if (!toAccessor->isMutating()) {
selfExpr->setType(selfTy);
} else {
// Access the base as inout if the accessor is mutating.
auto lvTy = LValueType::get(selfTy);
selfExpr->setType(lvTy);
selfExpr->propagateLValueAccessKind(AccessKind::ReadWrite);
selfExpr = new (Context) InOutExpr(SourceLoc(),
selfExpr, selfTy, /*implicit*/ true);
}
return selfExpr;
};
{
auto getter = VD->getGetter();
assert(getter);
Expr *selfExpr = makeSelfExpr(getter, ValueImpl->getGetter());
auto implRef = ConcreteDeclRef(Context, ValueImpl, SelfContextSubs);
auto implMemberExpr = new (Context) MemberRefExpr(selfExpr,
SourceLoc(),
implRef,
DeclNameLoc(),
/*implicit*/ true);
Expr *returnExpr;
if (ValueImpl->isSettable(VD->getDeclContext())) {
auto valueLVTy = LValueType::get(valueTy);
implMemberExpr->setType(valueLVTy);
implMemberExpr->propagateLValueAccessKind(AccessKind::Read);
returnExpr = new (Context) LoadExpr(implMemberExpr,
valueTy);
returnExpr->setImplicit();
} else {
implMemberExpr->setType(valueTy);
returnExpr = implMemberExpr;
}
auto returnStmt = new (Context) ReturnStmt(SourceLoc(), returnExpr,
/*implicit*/ true);
bodyStmts.push_back(returnStmt);
auto body = BraceStmt::create(Context, SourceLoc(), bodyStmts, SourceLoc(),
/*implicit*/ true);
getter->setBody(body);
getter->setBodyTypeCheckedIfPresent();
}
bodyStmts.clear();
if (auto setter = VD->getSetter()) {
Expr *selfExpr = makeSelfExpr(setter, ValueImpl->getSetter());
auto implRef = ConcreteDeclRef(Context, ValueImpl, SelfContextSubs);
auto implMemberExpr = new (Context) MemberRefExpr(selfExpr,
SourceLoc(),
implRef,
DeclNameLoc(),
/*implicit*/ true);
auto valueLVTy = LValueType::get(valueTy);
implMemberExpr->setType(valueLVTy);
implMemberExpr->propagateLValueAccessKind(AccessKind::Write);
ConcreteDeclRef newValueRef = getFirstParamDecl(setter);
auto newValueExpr = new (Context) DeclRefExpr(newValueRef, DeclNameLoc(),
/*implicit*/ true);
newValueExpr->setType(valueTy);
auto assign = new (Context) AssignExpr(implMemberExpr, SourceLoc(),
newValueExpr, /*implicit*/ true);
assign->setType(TupleType::getEmpty(Context));
bodyStmts.push_back(assign);
auto body = BraceStmt::create(Context, SourceLoc(), bodyStmts, SourceLoc(),
/*implicit*/ true);
setter->setBody(body);
setter->setBodyTypeCheckedIfPresent();
}
}
void TypeChecker::completeLazyVarImplementation(VarDecl *VD) {
assert(VD->getAttrs().hasAttribute<LazyAttr>());
assert(VD->getStorageKind() == AbstractStorageDecl::Computed &&
"variable not validated yet");
assert(!VD->isStatic() && "Static vars are already lazy on their own");
// Create the storage property as an optional of VD's type.
SmallString<64> NameBuf = VD->getName().str();
NameBuf += ".storage";
auto StorageName = Context.getIdentifier(NameBuf);
auto StorageTy = OptionalType::get(VD->getType());
auto StorageInterfaceTy = OptionalType::get(VD->getInterfaceType());
auto *Storage = new (Context) VarDecl(/*IsStatic*/false, VarDecl::Specifier::Var,
/*IsCaptureList*/false, VD->getLoc(),
StorageName, StorageTy,
VD->getDeclContext());
Storage->setInterfaceType(StorageInterfaceTy);
Storage->setUserAccessible(false);
addMemberToContextIfNeeded(Storage, VD->getDeclContext(), VD);
// Create the pattern binding decl for the storage decl. This will get
// default initialized to nil.
Pattern *PBDPattern = new (Context) NamedPattern(Storage, /*implicit*/true);
PBDPattern = new (Context) TypedPattern(PBDPattern,
TypeLoc::withoutLoc(StorageTy),
/*implicit*/true);
auto *PBD = PatternBindingDecl::create(Context, /*staticloc*/SourceLoc(),
StaticSpellingKind::None,
/*varloc*/VD->getLoc(),
PBDPattern, /*init*/nullptr,
VD->getDeclContext());
PBD->setImplicit();
addMemberToContextIfNeeded(PBD, VD->getDeclContext(), VD);
// Now that we've got the storage squared away, synthesize the getter.
completeLazyPropertyGetter(VD, Storage, *this);
// The setter just forwards on to storage without materializing the initial
// value.
auto *Set = VD->getSetter();
VarDecl *SetValueDecl = getFirstParamDecl(Set);
// FIXME: This is wrong for observed properties.
synthesizeTrivialSetter(Set, Storage, SetValueDecl, *this);
// Mark the vardecl to be final, implicit, and private. In a class, this
// prevents it from being dynamically dispatched. Note that we do this after
// the accessors are set up, because we don't want the setter for the lazy
// property to inherit these properties from the storage.
if (VD->getDeclContext()->getAsClassOrClassExtensionContext())
makeFinal(Context, Storage);
Storage->setImplicit();
Storage->setAccess(AccessLevel::Private);
Storage->setSetterAccess(AccessLevel::Private);
}
/// Consider add a materializeForSet accessor to the given storage
/// decl (which has accessors).
void swift::maybeAddMaterializeForSet(AbstractStorageDecl *storage,
TypeChecker &TC) {
assert(storage->hasAccessorFunctions());
// Be idempotent. There are a bunch of places where we want to
// ensure that there's a materializeForSet accessor.
if (storage->getMaterializeForSetFunc()) return;
// Never add materializeForSet to readonly declarations.
if (!storage->getSetter()) return;
// We only need materializeForSet in type contexts.
auto *dc = storage->getDeclContext();
if (!dc->isTypeContext())
return;
// Requirements of ObjC protocols don't need this.
if (auto protoDecl = dyn_cast<ProtocolDecl>(dc))
if (protoDecl->isObjC())
return;
// Members of structs imported by Clang don't need this, because we can
// synthesize it later.
if (auto structDecl = dyn_cast<StructDecl>(dc))
if (structDecl->hasClangNode())
return;
addMaterializeForSet(storage, TC);
}
void swift::maybeAddAccessorsToVariable(VarDecl *var, TypeChecker &TC) {
if (var->getGetter())
return;
auto *dc = var->getDeclContext();
assert(!var->hasAccessorFunctions());
// Introduce accessors for a property with behaviors.
if (var->hasBehavior()) {
assert(!var->getBehavior()->Conformance.hasValue());
// The property should be considered computed by the time we're through.
SWIFT_DEFER {
assert(!var->hasStorage() && "behavior var was not made computed");
};
auto behavior = var->getMutableBehavior();
NormalProtocolConformance *conformance = nullptr;
VarDecl *valueProp = nullptr;
bool mightBeMutating = dc->isTypeContext()
&& !var->isStatic()
&& !dc->getDeclaredInterfaceType()->hasReferenceSemantics();
auto makeBehaviorAccessors = [&]{
FuncDecl *getter;
FuncDecl *setter = nullptr;
if (valueProp && valueProp->getGetter()) {
getter = createGetterPrototype(var, TC);
// The getter is mutating if the behavior implementation is, unless
// we're in a class or non-instance context.
if (mightBeMutating && valueProp->isGetterMutating())
getter->setSelfAccessKind(SelfAccessKind::Mutating);
getter->setAccess(var->getFormalAccess());
// Make a setter if the behavior property has one.
if (valueProp->getSetter()) {
ParamDecl *newValueParam = nullptr;
setter = createSetterPrototype(var, newValueParam, TC);
if (mightBeMutating && valueProp->isSetterMutating())
setter->setSelfAccessKind(SelfAccessKind::Mutating);
// TODO: max of property and implementation setter visibility?
setter->setAccess(var->getFormalAccess());
}
} else {
// Even if we couldn't find a value property, still make up a stub
// getter and setter, so that subsequent diagnostics make sense for a
// computed-ish property.
getter = createGetterPrototype(var, TC);
getter->setAccess(var->getFormalAccess());
ParamDecl *newValueParam = nullptr;
setter = createSetterPrototype(var, newValueParam, TC);
setter->setSelfAccessKind(SelfAccessKind::NonMutating);
setter->setAccess(var->getFormalAccess());
}
var->makeComputed(SourceLoc(), getter, setter, nullptr, SourceLoc());
// Save the conformance and 'value' decl for later type checking.
behavior->Conformance = conformance;
behavior->ValueDecl = valueProp;
addMemberToContextIfNeeded(getter, dc, var);
if (setter)
addMemberToContextIfNeeded(setter, dc, getter);
};
// Try to resolve the behavior to a protocol.
auto behaviorType = TC.resolveType(behavior->ProtocolName, dc,
TypeResolutionOptions());
if (!behaviorType) {
return makeBehaviorAccessors();
}
{
// The type must refer to a protocol.
auto behaviorProtoTy = behaviorType->getAs<ProtocolType>();
if (!behaviorProtoTy) {
TC.diagnose(behavior->getLoc(),
diag::property_behavior_not_protocol);
behavior->Conformance = (NormalProtocolConformance*)nullptr;
return makeBehaviorAccessors();
}
auto behaviorProto = behaviorProtoTy->getDecl();
// Validate the behavior protocol and all its extensions so we can do
// name lookup.
TC.validateDecl(behaviorProto);
for (auto ext : behaviorProto->getExtensions()) {
TC.validateExtension(ext);
}
// Look up the behavior protocol's "value" property, or bail if it doesn't
// have one. The property's accessors will decide whether the getter
// is mutating, and whether there's a setter. We'll type-check to make
// sure the property type matches later after validation.
auto lookup = TC.lookupMember(dc, behaviorProtoTy, TC.Context.Id_value);
for (auto found : lookup) {
if (auto foundVar = dyn_cast<VarDecl>(found.getValueDecl())) {
if (valueProp) {
TC.diagnose(behavior->getLoc(),
diag::property_behavior_protocol_reqt_ambiguous,
TC.Context.Id_value);
TC.diagnose(valueProp->getLoc(),
diag::property_behavior_protocol_reqt_here,
TC.Context.Id_value);
TC.diagnose(foundVar->getLoc(),
diag::property_behavior_protocol_reqt_here,
TC.Context.Id_value);
break;
}
valueProp = foundVar;
}
}
if (!valueProp) {
TC.diagnose(behavior->getLoc(),
diag::property_behavior_protocol_no_value);
return makeBehaviorAccessors();
}
TC.validateDecl(valueProp);
var->setIsGetterMutating(mightBeMutating &&
valueProp->isGetterMutating());
var->setIsSetterMutating(mightBeMutating &&
valueProp->isSetterMutating());
// Set up a conformance to represent the behavior instantiation.
// The conformance will be on the containing 'self' type, or '()' if the
// property is in a non-type context.
Type behaviorSelf;
if (dc->isTypeContext()) {
behaviorSelf = dc->getSelfTypeInContext();
assert(behaviorSelf && "type context doesn't have self type?!");
if (var->isStatic())
behaviorSelf = MetatypeType::get(behaviorSelf);
} else {
behaviorSelf = TC.Context.TheEmptyTupleType;
}
conformance = TC.Context.getBehaviorConformance(behaviorSelf,
behaviorProto,
behavior->getLoc(), var,
ProtocolConformanceState::Checking);
}
return makeBehaviorAccessors();
}
// Lazy properties require special handling.
if (var->getAttrs().hasAttribute<LazyAttr>()) {
auto *getter = createGetterPrototype(var, TC);
// lazy getters are mutating on an enclosing value type.
if (!dc->getAsClassOrClassExtensionContext()) {
getter->setSelfAccessKind(SelfAccessKind::Mutating);
var->setIsGetterMutating(true);
}
getter->setAccess(var->getFormalAccess());
ParamDecl *newValueParam = nullptr;
auto *setter = createSetterPrototype(var, newValueParam, TC);
FuncDecl *materializeForSet = nullptr;
if (dc->getAsNominalTypeOrNominalTypeExtensionContext())
materializeForSet = createMaterializeForSetPrototype(var, setter, TC);
var->makeComputed(SourceLoc(), getter, setter, materializeForSet, SourceLoc());
addMemberToContextIfNeeded(getter, dc, var);
addMemberToContextIfNeeded(setter, dc, getter);
if (materializeForSet)
addMemberToContextIfNeeded(materializeForSet, dc, setter);
return;
}
// Local variables don't otherwise get accessors.
if (dc->isLocalContext())
return;
// Implicit properties don't get accessors.
if (var->isImplicit())
return;
if (!dc->isTypeContext()) {
// Fixed-layout global variables don't get accessors.
if (var->hasFixedLayout())
return;
// In a protocol context, variables written as just "var x : Int" or
// "let x : Int" are errors and recovered by building a computed property
// with just a getter. Diagnose this and create the getter decl now.
} else if (isa<ProtocolDecl>(dc)) {
if (var->hasStorage()) {
if (var->isLet())
TC.diagnose(var->getLoc(),
diag::protocol_property_must_be_computed_var);
else
TC.diagnose(var->getLoc(), diag::protocol_property_must_be_computed);
convertStoredVarInProtocolToComputed(var, TC);
}
return;
// NSManaged properties on classes require special handling.
} else if (dc->getAsClassOrClassExtensionContext()) {
if (var->getAttrs().hasAttribute<NSManagedAttr>()) {
convertNSManagedStoredVarToComputed(var, TC);
return;
}
// Stored properties imported from Clang don't get accessors.
} else if (auto *structDecl = dyn_cast<StructDecl>(dc)) {
if (structDecl->hasClangNode())
return;
}
// Stored properties in SIL mode don't get accessors.
if (auto sourceFile = dc->getParentSourceFile())
if (sourceFile->Kind == SourceFileKind::SIL)
return;
// Everything else gets accessors.
addTrivialAccessorsToStorage(var, TC);
}
/// \brief Create an implicit struct or class constructor.
///
/// \param decl The struct or class for which a constructor will be created.
/// \param ICK The kind of implicit constructor to create.
///
/// \returns The newly-created constructor, which has already been type-checked
/// (but has not been added to the containing struct or class).
ConstructorDecl *swift::createImplicitConstructor(TypeChecker &tc,
NominalTypeDecl *decl,
ImplicitConstructorKind ICK) {
ASTContext &context = tc.Context;
SourceLoc Loc = decl->getLoc();
auto accessLevel = AccessLevel::Internal;
if (decl->hasClangNode())
accessLevel = std::max(accessLevel, decl->getFormalAccess());
// Determine the parameter type of the implicit constructor.
SmallVector<ParamDecl*, 8> params;
if (ICK == ImplicitConstructorKind::Memberwise) {
assert(isa<StructDecl>(decl) && "Only struct have memberwise constructor");
// Computed and static properties are not initialized.
for (auto var : decl->getStoredProperties()) {
if (var->isImplicit())
continue;
tc.validateDecl(var);
// Initialized 'let' properties have storage, but don't get an argument
// to the memberwise initializer since they already have an initial
// value that cannot be overridden.
if (var->isLet() && var->getParentInitializer())
continue;
accessLevel = std::min(accessLevel, var->getFormalAccess());
auto varType = var->getType()
->getReferenceStorageReferent();
auto varInterfaceType = var->getInterfaceType()
->getReferenceStorageReferent();
// If var is a lazy property, its value is provided for the underlying
// storage. We thus take an optional of the properties type. We only
// need to do this because the implicit constructor is added before all
// the properties are type checked. Perhaps init() synth should be moved
// later.
if (var->getAttrs().hasAttribute<LazyAttr>()) {
varType = OptionalType::get(varType);
varInterfaceType = OptionalType::get(varInterfaceType);
}
// Create the parameter.
auto *arg = new (context) ParamDecl(VarDecl::Specifier::Owned, SourceLoc(),
Loc, var->getName(),
Loc, var->getName(), varType, decl);
arg->setInterfaceType(varInterfaceType);
arg->setImplicit();
params.push_back(arg);
}
}
auto paramList = ParameterList::create(context, params);
// Create the constructor.
DeclName name(context, context.Id_init, paramList);
auto *selfParam = ParamDecl::createSelf(Loc, decl,
/*static*/false, /*inout*/true);
auto *ctor =
new (context) ConstructorDecl(name, Loc,
OTK_None, /*FailabilityLoc=*/SourceLoc(),
/*Throws=*/false, /*ThrowsLoc=*/SourceLoc(),
selfParam, paramList,
nullptr, decl);
// Mark implicit.
ctor->setImplicit();
ctor->setAccess(accessLevel);
if (ICK == ImplicitConstructorKind::Memberwise)
ctor->setIsMemberwiseInitializer();
// If we are defining a default initializer for a class that has a superclass,
// it overrides the default initializer of its superclass. Add an implicit
// 'override' attribute.
if (auto classDecl = dyn_cast<ClassDecl>(decl)) {
if (classDecl->getSuperclass())
ctor->getAttrs().add(new (tc.Context) OverrideAttr(/*IsImplicit=*/true));
}
// Type-check the constructor declaration.
tc.typeCheckDecl(ctor, /*isFirstPass=*/true);
// If the struct in which this constructor is being added was imported,
// add it as an external definition.
if (decl->hasClangNode()) {
tc.Context.addExternalDecl(ctor);
}
return ctor;
}
/// Create a stub body that emits a fatal error message.
static void createStubBody(TypeChecker &tc, ConstructorDecl *ctor) {
auto unimplementedInitDecl = tc.Context.getUnimplementedInitializerDecl(&tc);
auto classDecl = ctor->getDeclContext()->getAsClassOrClassExtensionContext();
if (!unimplementedInitDecl) {
tc.diagnose(classDecl->getLoc(), diag::missing_unimplemented_init_runtime);
return;
}
// Create a call to Swift._unimplementedInitializer
auto loc = classDecl->getLoc();
Expr *fn = new (tc.Context) DeclRefExpr(unimplementedInitDecl,
DeclNameLoc(loc),
/*Implicit=*/true);
llvm::SmallString<64> buffer;
StringRef fullClassName = tc.Context.AllocateCopy(
(classDecl->getModuleContext()->getName().str() +
"." +
classDecl->getName().str()).toStringRef(buffer));
Expr *className = new (tc.Context) StringLiteralExpr(fullClassName, loc,
/*Implicit=*/true);
Expr *call = CallExpr::createImplicit(tc.Context, fn, { className },
{ tc.Context.Id_className });
ctor->setBody(BraceStmt::create(tc.Context, SourceLoc(),
ASTNode(call),
SourceLoc(),
/*implicit=*/true));
// Note that this is a stub implementation.
ctor->setStubImplementation(true);
}
ConstructorDecl *
swift::createDesignatedInitOverride(TypeChecker &tc,
ClassDecl *classDecl,
ConstructorDecl *superclassCtor,
DesignatedInitKind kind) {
// FIXME: Inheriting initializers that have their own generic parameters
if (superclassCtor->getGenericParams())
return nullptr;
// Lookup will sometimes give us initializers that are from the ancestors of
// our immediate superclass. So, from the superclass constructor, we look
// one level up to the enclosing type context which will either be a class
// or an extension. We can use the type declared in that context to check
// if it's our immediate superclass and give up if we didn't.
//
// FIXME: Remove this when lookup of initializers becomes restricted to our
// immediate superclass.
auto *superclassCtorDecl =
superclassCtor->getDeclContext()
->getAsNominalTypeOrNominalTypeExtensionContext();
Type superclassTy = classDecl->getSuperclass();
Type superclassTyInContext = classDecl->mapTypeIntoContext(superclassTy);
NominalTypeDecl *superclassDecl = superclassTy->getAnyNominal();
if (superclassCtorDecl != superclassDecl) {
return nullptr;
}
// Determine the initializer parameters.
auto &ctx = tc.Context;
// Create the 'self' declaration and patterns.
auto *selfDecl = ParamDecl::createSelf(SourceLoc(), classDecl);
// Create the initializer parameter patterns.
OptionSet<ParameterList::CloneFlags> options = ParameterList::Implicit;
options |= ParameterList::Inherited;
auto *bodyParams = superclassCtor->getParameterList(1)->clone(ctx,options);
// If the superclass is generic, we need to map the superclass constructor's
// parameter types into the generic context of our class.
//
// We might have to apply substitutions, if for example we have a declaration
// like 'class A : B<Int>'.
if (superclassDecl->getGenericSignatureOfContext()) {
auto *moduleDecl = classDecl->getParentModule();
auto subMap = superclassTyInContext->getContextSubstitutionMap(
moduleDecl,
superclassDecl,
classDecl->getGenericEnvironment());
for (auto *decl : *bodyParams) {
auto paramTy = decl->getInterfaceType();
// Apply the superclass substitutions to produce a contextual
// type in terms of the derived class archetypes.
auto paramSubstTy = paramTy.subst(subMap);
decl->setType(paramSubstTy);
// Map it to an interface type in terms of the derived class
// generic signature.
decl->setInterfaceType(classDecl->mapTypeOutOfContext(paramSubstTy));
}
} else {
for (auto *decl : *bodyParams) {
if (!decl->hasType())
decl->setType(classDecl->mapTypeIntoContext(decl->getInterfaceType()));
}
}
// Create the initializer declaration, inheriting the name,
// failability, and throws from the superclass initializer.
auto ctor =
new (ctx) ConstructorDecl(superclassCtor->getFullName(),
classDecl->getBraces().Start,
superclassCtor->getFailability(),
/*FailabilityLoc=*/SourceLoc(),
/*Throws=*/superclassCtor->hasThrows(),
/*ThrowsLoc=*/SourceLoc(),
selfDecl, bodyParams,
/*GenericParams=*/nullptr, classDecl);
ctor->setImplicit();
AccessLevel access = classDecl->getFormalAccess();
access = std::max(access, AccessLevel::Internal);
access = std::min(access, superclassCtor->getFormalAccess());
ctor->setAccess(access);
// Inherit the @_versioned attribute.
if (superclassCtor->getAttrs().hasAttribute<VersionedAttr>()) {
auto *clonedAttr = new (ctx) VersionedAttr(/*implicit=*/true);
ctor->getAttrs().add(clonedAttr);
}
// Make sure the constructor is only as available as its superclass's
// constructor.
AvailabilityInference::applyInferredAvailableAttrs(ctor, superclassCtor, ctx);
// Set the interface type of the initializer.
ctor->setGenericEnvironment(classDecl->getGenericEnvironmentOfContext());
tc.configureInterfaceType(ctor, ctor->getGenericSignature());
if (superclassCtor->isObjC()) {
// Inherit the @objc name from the superclass initializer, if it
// has one.
if (auto objcAttr = superclassCtor->getAttrs().getAttribute<ObjCAttr>()) {
if (objcAttr->hasName()) {
auto *clonedAttr = objcAttr->clone(ctx);
clonedAttr->setImplicit(true);
ctor->getAttrs().add(clonedAttr);
}
}
auto errorConvention = superclassCtor->getForeignErrorConvention();
markAsObjC(tc, ctor, ObjCReason::ImplicitlyObjC, errorConvention);
}
if (superclassCtor->isRequired())
ctor->getAttrs().add(new (tc.Context) RequiredAttr(/*IsImplicit=*/true));
if (superclassCtor->isDynamic())
ctor->getAttrs().add(new (tc.Context) DynamicAttr(/*IsImplicit*/true));
// Wire up the overrides.
ctor->getAttrs().add(new (tc.Context) OverrideAttr(/*IsImplicit=*/true));
ctor->setOverriddenDecl(superclassCtor);
if (kind == DesignatedInitKind::Stub) {
// Make this a stub implementation.
createStubBody(tc, ctor);
ctor->setNeedsNewVTableEntry(false);
return ctor;
}
// Form the body of a chaining designated initializer.
assert(kind == DesignatedInitKind::Chaining);
// Reference to super.init.
Expr *superRef = new (ctx) SuperRefExpr(selfDecl, SourceLoc(),
/*Implicit=*/true);
Expr *ctorRef = new (ctx) UnresolvedDotExpr(superRef, SourceLoc(),
superclassCtor->getFullName(),
DeclNameLoc(),
/*Implicit=*/true);
auto ctorArgs = buildArgumentForwardingExpr(bodyParams->getArray(), ctx);
// If buildArgumentForwardingExpr failed, then it was because we tried to
// forward varargs, which cannot be done yet.
// TODO: We should be able to forward varargs!
if (!ctorArgs) {
tc.diagnose(classDecl->getLoc(),
diag::unsupported_synthesize_init_variadic,
classDecl->getDeclaredType());
tc.diagnose(superclassCtor, diag::variadic_superclass_init_here);
createStubBody(tc, ctor);
return ctor;
}
Expr *superCall =
CallExpr::create(ctx, ctorRef, ctorArgs,
superclassCtor->getFullName().getArgumentNames(), { },
/*hasTrailingClosure=*/false, /*implicit=*/true);
if (superclassCtor->hasThrows()) {
superCall = new (ctx) TryExpr(SourceLoc(), superCall, Type(),
/*implicit=*/true);
}
ctor->setBody(BraceStmt::create(tc.Context, SourceLoc(),
ASTNode(superCall),
SourceLoc(),
/*implicit=*/true));
return ctor;
}
void TypeChecker::addImplicitDestructor(ClassDecl *CD) {
if (CD->hasDestructor() || CD->isInvalid())
return;
auto *selfDecl = ParamDecl::createSelf(CD->getLoc(), CD);
auto *DD = new (Context) DestructorDecl(CD->getLoc(), selfDecl, CD);
DD->setImplicit();
// Type-check the destructor declaration.
typeCheckDecl(DD, /*isFirstPass=*/true);
// Create an empty body for the destructor.
DD->setBody(BraceStmt::create(Context, CD->getLoc(), { }, CD->getLoc(), true));
CD->addMember(DD);
CD->setHasDestructor();
}