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fuchsia / third_party / swift / refs/tags/swift-2.2-SNAPSHOT-2015-12-18-a / . / lib / Sema / CodeSynthesis.cpp
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//===--- TypeCheckDecl.cpp - Type Checking for Declarations ---------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://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/Attr.h"
#include "swift/AST/Availability.h"
#include "swift/AST/Expr.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 VarDecl *getParamDeclAtIndex(FuncDecl *fn, unsigned index) {
TuplePatternElt singleParam;
Pattern *paramPattern = fn->getBodyParamPatterns().back();
ArrayRef<TuplePatternElt> params;
if (auto paramTuple = dyn_cast<TuplePattern>(paramPattern)) {
params = paramTuple->getElements();
} else {
singleParam = TuplePatternElt(
cast<ParenPattern>(paramPattern)->getSubPattern());
params = singleParam;
}
auto firstParamPattern = params[index].getPattern();
return firstParamPattern->getSingleVar();
}
static VarDecl *getFirstParamDecl(FuncDecl *fn) {
return getParamDeclAtIndex(fn, 0);
};
/// \brief Build an implicit 'self' parameter for the specified DeclContext.
static Pattern *buildImplicitSelfParameter(SourceLoc Loc, DeclContext *DC) {
ASTContext &Ctx = DC->getASTContext();
auto *SelfDecl = new (Ctx) ParamDecl(/*IsLet*/ true, Loc, Identifier(),
Loc, Ctx.Id_self, Type(), DC);
SelfDecl->setImplicit();
Pattern *P = new (Ctx) NamedPattern(SelfDecl, /*Implicit=*/true);
return new (Ctx) TypedPattern(P, TypeLoc());
}
static TuplePatternElt buildArgumentPattern(SourceLoc loc, DeclContext *DC,
StringRef name, Type type,
bool isLet,
VarDecl **paramDecl,
ASTContext &Context) {
auto *param = new (Context) ParamDecl(isLet, SourceLoc(), Identifier(),
loc, Context.getIdentifier(name),
Type(), DC);
if (paramDecl) *paramDecl = param;
param->setImplicit();
Pattern *valuePattern
= new (Context) TypedPattern(new (Context) NamedPattern(param, true),
TypeLoc::withoutLoc(type));
valuePattern->setImplicit();
return TuplePatternElt(valuePattern);
}
static TuplePatternElt buildLetArgumentPattern(SourceLoc loc, DeclContext *DC,
StringRef name, Type type,
VarDecl **paramDecl,
ASTContext &ctx) {
return buildArgumentPattern(loc, DC, name, type,
/*isLet*/ true, paramDecl, ctx);
}
static TuplePatternElt buildInOutArgumentPattern(SourceLoc loc, DeclContext *DC,
StringRef name, Type type,
VarDecl **paramDecl,
ASTContext &ctx) {
return buildArgumentPattern(loc, DC, name, InOutType::get(type),
/*isLet*/ false, paramDecl, ctx);
}
static Type getTypeOfStorage(AbstractStorageDecl *storage,
TypeChecker &TC) {
if (auto var = dyn_cast<VarDecl>(storage)) {
return TC.getTypeOfRValue(var, /*want interface type*/ false);
} else {
// None of the transformations done by getTypeOfRValue are
// necessary for subscripts.
auto subscript = cast<SubscriptDecl>(storage);
return subscript->getElementType();
}
}
static TuplePatternElt
buildSetterValueArgumentPattern(AbstractStorageDecl *storage,
VarDecl **valueDecl, TypeChecker &TC) {
auto storageType = getTypeOfStorage(storage, TC);
return buildLetArgumentPattern(storage->getLoc(),
storage->getDeclContext(),
"value", storageType, valueDecl, TC.Context);
}
/// Build a pattern which can forward the formal index parameters of a
/// declaration.
///
/// \param prefix optional arguments to be prefixed onto the index
/// forwarding pattern
static Pattern *buildIndexForwardingPattern(AbstractStorageDecl *storage,
MutableArrayRef<TuplePatternElt> prefix,
TypeChecker &TC) {
auto subscript = dyn_cast<SubscriptDecl>(storage);
// Fast path: if this isn't a subscript, and we have a first
// pattern, we can just use that.
if (!subscript) {
auto tuple = TuplePattern::createSimple(TC.Context, SourceLoc(), prefix,
SourceLoc());
tuple->setImplicit();
return tuple;
}
// Otherwise, we need to build up a new TuplePattern.
SmallVector<TuplePatternElt, 4> elements;
// Start with the fields from the first pattern, if there are any.
elements.append(prefix.begin(), prefix.end());
// Clone index patterns in a manner that allows them to be
// perfectly forwarded.
DeclContext *DC = storage->getDeclContext();
auto addVarPatternFor = [&](Pattern *P, Identifier label = Identifier()) {
Pattern *vp = P->cloneForwardable(TC.Context, DC, Pattern::Implicit);
elements.push_back(TuplePatternElt(vp));
elements.back().setLabel(label, SourceLoc());
};
// This is the same breakdown the parser does.
auto indices = subscript->getIndices();
if (auto pp = dyn_cast<ParenPattern>(indices)) {
addVarPatternFor(pp);
} else {
auto tp = cast<TuplePattern>(indices);
for (auto &element : tp->getElements()) {
addVarPatternFor(element.getPattern(), element.getLabel());
}
}
return TuplePattern::createSimple(TC.Context, SourceLoc(), elements,
SourceLoc());
}
static FuncDecl *createGetterPrototype(AbstractStorageDecl *storage,
TypeChecker &TC) {
SourceLoc loc = storage->getLoc();
// Create the parameter list for the getter.
SmallVector<Pattern *, 2> getterParams;
// The implicit 'self' argument if in a type context.
if (storage->getDeclContext()->isTypeContext())
getterParams.push_back(
buildImplicitSelfParameter(loc, storage->getDeclContext()));
// Add an index-forwarding clause.
getterParams.push_back(buildIndexForwardingPattern(storage, {}, TC));
SourceLoc staticLoc;
if (auto var = dyn_cast<VarDecl>(storage)) {
if (var->isStatic())
staticLoc = var->getLoc();
}
auto storageType = getTypeOfStorage(storage, TC);
auto getter = FuncDecl::create(
TC.Context, staticLoc, StaticSpellingKind::None, loc, Identifier(), loc,
SourceLoc(), SourceLoc(), /*GenericParams=*/nullptr, Type(), getterParams,
TypeLoc::withoutLoc(storageType), storage->getDeclContext());
getter->setImplicit();
if (storage->isGetterMutating())
getter->setMutating();
// If the var is marked final, then so is the getter.
if (storage->isFinal())
makeFinal(TC.Context, getter);
if (storage->isStatic())
getter->setStatic();
return getter;
}
static FuncDecl *createSetterPrototype(AbstractStorageDecl *storage,
VarDecl *&valueDecl,
TypeChecker &TC) {
SourceLoc loc = storage->getLoc();
// Create the parameter list for the setter.
SmallVector<Pattern *, 2> params;
// The implicit 'self' argument if in a type context.
if (storage->getDeclContext()->isTypeContext()) {
params.push_back(
buildImplicitSelfParameter(loc, storage->getDeclContext()));
}
// Add a "(value : T, indices...)" pattern.
TuplePatternElt valuePattern =
buildSetterValueArgumentPattern(storage, &valueDecl, TC);
params.push_back(buildIndexForwardingPattern(storage, valuePattern, TC));
Type setterRetTy = TupleType::getEmpty(TC.Context);
FuncDecl *setter = FuncDecl::create(
TC.Context, /*StaticLoc=*/SourceLoc(), StaticSpellingKind::None, loc,
Identifier(), loc, SourceLoc(), SourceLoc(), /*generic=*/nullptr, Type(),
params, TypeLoc::withoutLoc(setterRetTy), storage->getDeclContext());
setter->setImplicit();
if (!storage->isSetterNonMutating())
setter->setMutating();
// If the var is marked final, then so is the getter.
if (storage->isFinal())
makeFinal(TC.Context, setter);
if (storage->isStatic())
setter->setStatic();
return setter;
}
/// Returns the type of the self argument of a materializeForSet
/// callback. If we don't have a meaningful direct self type, just
/// use something meaningless and hope it doesn't matter.
static Type getSelfTypeForMaterializeForSetCallback(ASTContext &ctx,
DeclContext *DC,
bool isStatic) {
Type selfType = DC->getDeclaredTypeInContext();
if (!selfType) {
// This restriction is theoretically liftable by writing the necessary
// contextual information into the callback storage.
assert(!DC->isGenericContext() &&
"no enclosing type for generic materializeForSet; callback "
"will not be able to bind type arguments!");
return TupleType::getEmpty(ctx);
}
// If we're in a protocol, we want to actually use the Self type.
if (selfType->is<ProtocolType>()) {
selfType = DC->getProtocolSelf()->getArchetype();
}
// Use the metatype if this is a static member.
if (isStatic) {
return MetatypeType::get(selfType, ctx);
} else {
return selfType;
}
}
// 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 type.
auto nominal = dyn_cast<NominalTypeDecl>(storage->getDeclContext());
if (!nominal)
return false;
return nominal->hasClangNode();
}
static Type createMaterializeForSetReturnType(AbstractStorageDecl *storage,
TypeChecker &TC) {
auto &ctx = storage->getASTContext();
SourceLoc loc = storage->getLoc();
auto DC = storage->getDeclContext();
if (DC->getDeclaredTypeInContext() &&
DC->getDeclaredTypeInContext()->is<ErrorType>()) {
return ErrorType::get(ctx);
}
Type callbackSelfType =
getSelfTypeForMaterializeForSetCallback(ctx, DC, storage->isStatic());
TupleTypeElt callbackArgs[] = {
ctx.TheRawPointerType,
InOutType::get(ctx.TheUnsafeValueBufferType),
InOutType::get(callbackSelfType),
MetatypeType::get(callbackSelfType, MetatypeRepresentation::Thick),
};
auto callbackExtInfo = FunctionType::ExtInfo()
.withRepresentation(FunctionType::Representation::Thin);
auto callbackType = FunctionType::get(TupleType::get(callbackArgs, ctx),
TupleType::getEmpty(ctx),
callbackExtInfo);
// Try to make the callback type optional. Don't crash if it doesn't
// work, though.
auto optCallbackType = TC.getOptionalType(loc, callbackType);
if (!optCallbackType) optCallbackType = callbackType;
TupleTypeElt retElts[] = {
{ ctx.TheRawPointerType },
{ optCallbackType },
};
return TupleType::get(retElts, ctx);
}
static FuncDecl *createMaterializeForSetPrototype(AbstractStorageDecl *storage,
VarDecl *&bufferParamDecl,
TypeChecker &TC) {
auto &ctx = storage->getASTContext();
SourceLoc loc = storage->getLoc();
// Create the parameter list:
SmallVector<Pattern *, 2> params;
// - The implicit 'self' argument if in a type context.
auto DC = storage->getDeclContext();
if (DC->isTypeContext())
params.push_back(buildImplicitSelfParameter(loc, DC));
// - The buffer parameter, (buffer: Builtin.RawPointer,
// inout storage: Builtin.UnsafeValueBuffer,
// indices...).
TuplePatternElt bufferElements[] = {
buildLetArgumentPattern(loc, DC, "buffer", ctx.TheRawPointerType,
&bufferParamDecl, TC.Context),
buildInOutArgumentPattern(loc, DC, "callbackStorage",
ctx.TheUnsafeValueBufferType,
nullptr, TC.Context),
};
params.push_back(buildIndexForwardingPattern(storage, bufferElements, TC));
// The accessor returns (Builtin.RawPointer, (@convention(thin) (...) -> ())?),
// where the first pointer is the materialized address and the
// second is an optional callback.
Type retTy = createMaterializeForSetReturnType(storage, TC);
auto *materializeForSet = FuncDecl::create(
ctx, /*StaticLoc=*/SourceLoc(), StaticSpellingKind::None, loc,
Identifier(), loc, SourceLoc(), SourceLoc(), /*generic=*/nullptr, Type(),
params, TypeLoc::withoutLoc(retTy), DC);
materializeForSet->setImplicit();
// materializeForSet is mutating and static if the setter is.
auto setter = storage->getSetter();
materializeForSet->setMutating(setter->isMutating());
materializeForSet->setStatic(setter->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);
}
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.addedExternalDecl(materializeForSet);
return materializeForSet;
}
void swift::convertStoredVarInProtocolToComputed(VarDecl *VD, TypeChecker &TC) {
auto *Get = createGetterPrototype(VD, TC);
// Okay, we have both the getter and setter. Set them in VD.
VD->makeComputed(VD->getLoc(), Get, nullptr, nullptr, VD->getLoc());
// We've added some members to our containing class, add them to the members
// list.
addMemberToContextIfNeeded(Get, VD->getDeclContext());
// Type check the getter declaration.
TC.typeCheckDecl(VD->getGetter(), true);
TC.typeCheckDecl(VD->getGetter(), false);
}
/// Build a tuple around the given arguments.
static Expr *buildTupleExpr(ASTContext &ctx, ArrayRef<Expr*> args) {
if (args.size() == 1) {
return args[0];
}
SmallVector<Identifier, 4> labels(args.size());
SmallVector<SourceLoc, 4> labelLocs(args.size());
return TupleExpr::create(ctx, SourceLoc(), args, labels, labelLocs,
SourceLoc(), false, IsImplicit);
}
static Expr *buildTupleForwardingRefExpr(ASTContext &ctx,
ArrayRef<TuplePatternElt> params,
ArrayRef<TupleTypeElt> formalIndexTypes) {
assert(params.size() == formalIndexTypes.size());
SmallVector<Identifier, 4> labels;
SmallVector<SourceLoc, 4> labelLocs;
SmallVector<Expr *, 4> args;
for (unsigned i = 0, e = params.size(); i != e; ++i) {
const Pattern *param = params[i].getPattern();
args.push_back(param->buildForwardingRefExpr(ctx));
labels.push_back(formalIndexTypes[i].getName());
labelLocs.push_back(SourceLoc());
}
// A single unlabelled value is not a tuple.
if (args.size() == 1 && labels[0].empty())
return args[0];
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.
TuplePatternElt singleParam;
Pattern *paramPattern = accessor->getBodyParamPatterns().back();
ArrayRef<TuplePatternElt> params;
if (auto paramTuple = dyn_cast<TuplePattern>(paramPattern)) {
params = paramTuple->getElements();
} else {
singleParam = TuplePatternElt(
cast<ParenPattern>(paramPattern)->getSubPattern());
params = singleParam;
}
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);
// Look for formal subscript labels.
auto subscript = cast<SubscriptDecl>(accessor->getAccessorStorageDecl());
auto indexType = subscript->getIndicesType();
if (auto indexTuple = indexType->getAs<TupleType>()) {
return buildTupleForwardingRefExpr(ctx, params, indexTuple->getElements());
} else {
return buildTupleForwardingRefExpr(ctx, params, TupleTypeElt(indexType));
}
}
enum class SelfAccessKind {
/// 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,
SelfAccessKind selfAccessKind,
TypeChecker &TC) {
switch (selfAccessKind) {
case SelfAccessKind::Peer:
return new (TC.Context) DeclRefExpr(selfDecl, SourceLoc(), IsImplicit);
case SelfAccessKind::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) {}
virtual ~AccessorStorageReferenceContext() = default;
VarDecl *getSelfDecl() const override {
return Accessor->getImplicitSelfDecl();
}
Expr *getIndexRefExpr(ASTContext &ctx,
SubscriptDecl *subscript) const override {
return buildSubscriptIndexReference(ctx, Accessor);
}
};
}
/// Build an l-value for the storage of a declaration.
static Expr *buildStorageReference(
const StorageReferenceContext &referenceContext,
AbstractStorageDecl *storage,
AccessSemantics semantics,
SelfAccessKind selfAccessKind,
TypeChecker &TC) {
ASTContext &ctx = TC.Context;
VarDecl *selfDecl = referenceContext.getSelfDecl();
if (!selfDecl) {
return new (ctx) DeclRefExpr(storage, SourceLoc(), IsImplicit, semantics);
}
// If we should use a super access if applicable, and we have an
// overridden decl, then use ordinary access to it.
if (selfAccessKind == SelfAccessKind::Super) {
if (auto overridden = storage->getOverriddenDecl()) {
storage = overridden;
semantics = AccessSemantics::Ordinary;
} else {
selfAccessKind = SelfAccessKind::Peer;
}
}
Expr *selfDRE = buildSelfReference(selfDecl, selfAccessKind, TC);
if (auto subscript = dyn_cast<SubscriptDecl>(storage)) {
Expr *indices = referenceContext.getIndexRefExpr(ctx, subscript);
return new (ctx) SubscriptExpr(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,
SourceLoc(), IsImplicit, semantics);
}
static Expr *buildStorageReference(FuncDecl *accessor,
AbstractStorageDecl *storage,
AccessSemantics semantics,
SelfAccessKind selfAccessKind,
TypeChecker &TC) {
return buildStorageReference(AccessorStorageReferenceContext(accessor),
storage, semantics, selfAccessKind, 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,
SelfAccessKind::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.getIdentifier("NSCopying"),
NL_QualifiedDefault | NL_KnownNonCascadingDependency,
/*resolver=*/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.copyWithZone(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 = TC.getTypeOfRValue(VD, /*want interface type*/false);
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 'copyWithZone'
// "Val")
// (paren_expr type='<null>'
// (nil_literal_expr type='<null>'))))
auto UDE = new (Ctx) UnresolvedDotExpr(Val, SourceLoc(),
Ctx.getIdentifier("copyWithZone"),
SourceLoc(), /*implicit*/true);
Expr *Nil = new (Ctx) NilLiteralExpr(SourceLoc(), /*implicit*/true);
Nil = new (Ctx) ParenExpr(SourceLoc(), Nil, SourceLoc(), false);
//- (id)copyWithZone:(NSZone *)zone;
Expr *Call = new (Ctx) CallExpr(UDE, Nil, /*implicit*/true);
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,
SelfAccessKind::Super, TC);
body.push_back(new (TC.Context) AssignExpr(dest, SourceLoc(), value,
IsImplicit));
}
/// 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).
static void maybeMarkTransparent(FuncDecl *accessor,
AbstractStorageDecl *storage,
TypeChecker &TC) {
auto *NTD = storage->getDeclContext()
->isNominalTypeOrNominalTypeExtensionContext();
// FIXME: resilient global variables
if (!NTD || NTD->hasFixedLayout())
accessor->getAttrs().add(new (TC.Context) TransparentAttr(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 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));
maybeMarkTransparent(getter, storage, TC);
// Register the accessor as an external decl if the storage was imported.
if (needsToBeRegisteredAsExternalDecl(storage))
TC.Context.addedExternalDecl(getter);
}
/// Synthesize the body of a trivial setter.
static void synthesizeTrivialSetter(FuncDecl *setter,
AbstractStorageDecl *storage,
VarDecl *valueVar,
TypeChecker &TC) {
if (storage->isInvalid()) return;
auto &ctx = TC.Context;
SourceLoc loc = storage->getLoc();
auto *valueDRE = new (ctx) DeclRefExpr(valueVar, SourceLoc(), IsImplicit);
SmallVector<ASTNode, 1> setterBody;
createPropertyStoreOrCallSuperclassSetter(setter, valueDRE, storage,
setterBody, TC);
setter->setBody(BraceStmt::create(ctx, loc, setterBody, loc, true));
maybeMarkTransparent(setter, storage, TC);
// Register the accessor as an external decl if the storage was imported.
if (needsToBeRegisteredAsExternalDecl(storage))
TC.Context.addedExternalDecl(setter);
}
/// Build the result expression of a materializeForSet accessor.
///
/// \param address an expression yielding the address to return
/// \param callbackFn an optional closure expression for the callback
static Expr *buildMaterializeForSetResult(ASTContext &ctx, Expr *address,
Expr *callbackFn) {
if (!callbackFn) {
callbackFn = new (ctx) NilLiteralExpr(SourceLoc(), IsImplicit);
}
return TupleExpr::create(ctx, SourceLoc(), { address, callbackFn },
{ Identifier(), Identifier() },
{ SourceLoc(), SourceLoc() },
SourceLoc(), false, IsImplicit);
}
/// Create a call to the builtin function with the given name.
static Expr *buildCallToBuiltin(ASTContext &ctx, StringRef builtinName,
ArrayRef<Expr*> args) {
auto builtin = getBuiltinValueDecl(ctx, ctx.getIdentifier(builtinName));
Expr *builtinDRE = new (ctx) DeclRefExpr(builtin, SourceLoc(), IsImplicit);
Expr *arg = buildTupleExpr(ctx, args);
return new (ctx) CallExpr(builtinDRE, arg, IsImplicit);
}
/// Synthesize the body of a materializeForSet accessor for a stored
/// property.
static void synthesizeStoredMaterializeForSet(FuncDecl *materializeForSet,
AbstractStorageDecl *storage,
VarDecl *bufferDecl,
TypeChecker &TC) {
ASTContext &ctx = TC.Context;
// return (Builtin.addressof(&self.property), nil)
Expr *result = buildStorageReference(materializeForSet, storage,
AccessSemantics::DirectToStorage,
SelfAccessKind::Peer, TC);
result = new (ctx) InOutExpr(SourceLoc(), result, Type(), IsImplicit);
result = buildCallToBuiltin(ctx, "addressof", result);
result = buildMaterializeForSetResult(ctx, result, /*callback*/ nullptr);
ASTNode returnStmt = new (ctx) ReturnStmt(SourceLoc(), result, IsImplicit);
SourceLoc loc = storage->getLoc();
materializeForSet->setBody(BraceStmt::create(ctx, loc, returnStmt, loc,true));
maybeMarkTransparent(materializeForSet, storage, TC);
TC.typeCheckDecl(materializeForSet, true);
// Register the accessor as an external decl if the storage was imported.
if (needsToBeRegisteredAsExternalDecl(storage))
TC.Context.addedExternalDecl(materializeForSet);
}
/// 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 a materializeForSet accessor to the given declaration.
static FuncDecl *addMaterializeForSet(AbstractStorageDecl *storage,
TypeChecker &TC) {
VarDecl *bufferDecl;
auto materializeForSet =
createMaterializeForSetPrototype(storage, bufferDecl, TC);
addMemberToContextIfNeeded(materializeForSet, storage->getDeclContext(),
storage->getSetter());
storage->setMaterializeForSetFunc(materializeForSet);
TC.computeAccessibility(materializeForSet);
TC.validateDecl(materializeForSet);
return materializeForSet;
}
/// Add trivial accessors to a Stored or Addressed property.
void swift::addTrivialAccessorsToStorage(AbstractStorageDecl *storage,
TypeChecker &TC) {
assert(!storage->hasAccessorFunctions() && "already has accessors?");
// Create the getter.
auto *getter = createGetterPrototype(storage, TC);
// Create the setter.
FuncDecl *setter = nullptr;
VarDecl *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);
bool isDynamic = (storage->isDynamic() && storage->isObjC());
if (isDynamic)
getter->getAttrs().add(new (TC.Context) DynamicAttr(IsImplicit));
// Synthesize and type-check the body of the getter.
synthesizeTrivialGetter(getter, storage, TC);
TC.typeCheckDecl(getter, true);
TC.typeCheckDecl(getter, false);
if (setter) {
if (isDynamic)
setter->getAttrs().add(new (TC.Context) DynamicAttr(IsImplicit));
// Synthesize and type-check the body of the setter.
synthesizeTrivialSetter(setter, storage, setterValueParam, TC);
TC.typeCheckDecl(setter, true);
TC.typeCheckDecl(setter, false);
}
// We've added some members to our containing type, add them to the
// members list.
addMemberToContextIfNeeded(getter, storage->getDeclContext());
if (setter)
addMemberToContextIfNeeded(setter, storage->getDeclContext());
// Always add a materializeForSet when we're creating trivial
// accessors for a mutable stored property. We only do this when we
// need to be able to access something polymorphically, and we always
// want a materializeForSet in such situations.
if (setter) {
FuncDecl *materializeForSet = addMaterializeForSet(storage, TC);
synthesizeMaterializeForSet(materializeForSet, storage, TC);
TC.typeCheckDecl(materializeForSet, true);
TC.typeCheckDecl(materializeForSet, false);
}
}
/// 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 and type-check the body of the setter.
VarDecl *valueParamDecl = getFirstParamDecl(setter);
synthesizeTrivialSetter(setter, storage, valueParamDecl, TC);
TC.typeCheckDecl(setter, true);
TC.typeCheckDecl(setter, false);
}
/// 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()) {
addTrivialAccessorsToStorage(storage, *this);
return;
}
// Otherwise, if the requirement is settable, ensure that there's a
// materializeForSet function.
//
// @objc protocols don't need a materializeForSet since ObjC doesn't have
// that concept.
if (!requirement->isObjC() &&
requirement->getSetter() && !storage->getMaterializeForSetFunc()) {
FuncDecl *materializeForSet = addMaterializeForSet(storage, *this);
synthesizeMaterializeForSet(materializeForSet, storage, *this);
typeCheckDecl(materializeForSet, true);
typeCheckDecl(materializeForSet, false);
}
return;
}
using CallbackGenerator =
llvm::function_ref<void(SmallVectorImpl<ASTNode> &callbackBody,
VarDecl *selfDecl, VarDecl *bufferDecl,
VarDecl *callbackStorageDecl)>;
/// Build a materializeForSet callback function.
/// It should have type
/// (Builtin.RawPointer, inout Builtin.UnsafeValueBuffer,
/// inout T, T.Type) -> ()
static Expr *buildMaterializeForSetCallback(ASTContext &ctx,
FuncDecl *materializeForSet,
AbstractStorageDecl *storage,
const CallbackGenerator &generator) {
auto DC = storage->getDeclContext();
SourceLoc loc = storage->getLoc();
Type selfType =
getSelfTypeForMaterializeForSetCallback(ctx, DC,
materializeForSet->isStatic());
// Build the parameters pattern.
//
// Unexpected subtlety: it actually important to call the inout self
// parameter something other than 'self' so that we don't trigger
// the "implicit use of self" diagnostic.
VarDecl *bufferDecl;
VarDecl *callbackStorageDecl;
VarDecl *selfDecl;
TuplePatternElt argPatterns[] = {
buildLetArgumentPattern(loc, DC, "buffer", ctx.TheRawPointerType,
&bufferDecl, ctx),
buildInOutArgumentPattern(loc, DC, "callbackStorage",
ctx.TheUnsafeValueBufferType,
&callbackStorageDecl, ctx),
buildInOutArgumentPattern(loc, DC, "selfValue", selfType, &selfDecl, ctx),
buildLetArgumentPattern(loc, DC, "selfType", MetatypeType::get(selfType),
nullptr, ctx),
};
auto args = TuplePattern::createSimple(ctx, SourceLoc(), argPatterns,
SourceLoc());
args->setImplicit();
// Create the closure expression itself.
auto closure = new (ctx) ClosureExpr(args, SourceLoc(), SourceLoc(),
SourceLoc(), TypeLoc(),
/*discriminator*/ 0, materializeForSet);
// Generate the body of the closure.
SmallVector<ASTNode, 4> body;
generator(body, selfDecl, bufferDecl, callbackStorageDecl);
closure->setBody(BraceStmt::create(ctx, SourceLoc(), body, SourceLoc(),
IsImplicit),
/*isSingleExpression*/ false);
closure->setImplicit(IsImplicit);
// Call our special builtin to turn that into an opaque thin function.
auto result = buildCallToBuiltin(ctx, "makeMaterializeForSetCallback",
{ closure });
return result;
}
/// Build a builtin operation on a Builtin.UnsafeValueBuffer.
static Expr *buildValueBufferOperation(ASTContext &ctx, StringRef builtinName,
VarDecl *bufferDecl, Type valueType) {
// &buffer
Expr *bufferRef = new (ctx) DeclRefExpr(bufferDecl, SourceLoc(), IsImplicit);
bufferRef = new (ctx) InOutExpr(SourceLoc(), bufferRef, Type(), IsImplicit);
// T.self
Expr *metatypeRef = TypeExpr::createImplicit(valueType, ctx);
metatypeRef = new (ctx) DotSelfExpr(metatypeRef, SourceLoc(), SourceLoc());
metatypeRef->setImplicit(IsImplicit);
// Builtin.whatever(&buffer, T.self)
return buildCallToBuiltin(ctx, builtinName, { bufferRef, metatypeRef });
}
/// Build a call to Builtin.take.
static Expr *buildBuiltinTake(ASTContext &ctx, Expr *address,
Type valueType) {
// Builtin.take(address) as ValueType
Expr *result = buildCallToBuiltin(ctx, "take", { address });
result = new (ctx) CoerceExpr(result, SourceLoc(),
TypeLoc::withoutLoc(valueType));
result->setImplicit(IsImplicit);
return result;
}
/// Build an expression to initialize callback storage.
static ASTNode buildInitializeCallbackStorage(FuncDecl *materializeForSet,
Expr *initializer,
Type initializerType,
ASTContext &ctx) {
// let allocatedCallbackStorage =
// Builtin.allocateValueBuffer(&callbackStorage, IndexType.self))
VarDecl *callbackStorageDecl = getParamDeclAtIndex(materializeForSet, 1);
Expr *allocatedCallbackStorage =
buildValueBufferOperation(ctx, "allocValueBuffer", callbackStorageDecl,
initializerType);
// Builtin.initialize(indexArgs, allocatedCallbackStorage)
return buildCallToBuiltin(ctx, "initialize",
{ initializer, allocatedCallbackStorage });
}
/// Build an expression to take from callback storage.
static Expr *buildTakeFromCallbackStorage(VarDecl *storage, Type valueType,
ASTContext &ctx) {
Expr *address =
buildValueBufferOperation(ctx, "projectValueBuffer", storage, valueType);
return buildBuiltinTake(ctx, address, valueType);
}
namespace {
/// A reference to storage from the context of a materializeForSet
/// callback.
class CallbackStorageReferenceContext : public StorageReferenceContext {
VarDecl *Self;
VarDecl *CallbackStorage;
public:
CallbackStorageReferenceContext(VarDecl *self, VarDecl *callbackStorage)
: Self(self), CallbackStorage(callbackStorage) {}
virtual ~CallbackStorageReferenceContext() = default;
VarDecl *getSelfDecl() const override {
return Self;
}
Expr *getIndexRefExpr(ASTContext &ctx,
SubscriptDecl *subscript) const override {
return buildTakeFromCallbackStorage(CallbackStorage,
subscript->getIndicesType(), ctx);
}
};
}
/// Synthesize the body of a materializeForSet accessor for a
/// computed property.
static void synthesizeComputedMaterializeForSet(FuncDecl *materializeForSet,
AbstractStorageDecl *storage,
VarDecl *bufferDecl,
TypeChecker &TC) {
ASTContext &ctx = TC.Context;
SmallVector<ASTNode, 4> body;
AccessSemantics semantics;
// If the storage is dynamic, we must dynamically redispatch through the
// accessor. Otherwise, we can do a direct peer access.
if (needsDynamicMaterializeForSet(storage))
semantics = AccessSemantics::Ordinary;
else
semantics = AccessSemantics::DirectToAccessor;
// Builtin.initialize(self.property, buffer)
Expr *curValue = buildStorageReference(materializeForSet, storage,
semantics,
SelfAccessKind::Peer, TC);
Expr *bufferRef = new (ctx) DeclRefExpr(bufferDecl, SourceLoc(), IsImplicit);
body.push_back(buildCallToBuiltin(ctx, "initialize",
{ curValue, bufferRef }));
// If this is a subscript, preserve the index value:
if (auto subscript = dyn_cast<SubscriptDecl>(storage)) {
Expr *indices = buildSubscriptIndexReference(ctx, materializeForSet);
ASTNode initialize =
buildInitializeCallbackStorage(materializeForSet, indices,
subscript->getIndicesType(), ctx);
body.push_back(initialize);
}
// Build the callback.
Expr *callback =
buildMaterializeForSetCallback(ctx, materializeForSet, storage,
[&](SmallVectorImpl<ASTNode> &body,
VarDecl *selfDecl, VarDecl *bufferDecl,
VarDecl *callbackStorageDecl) {
// self.property = Builtin.take(buffer)
Expr *bufferRef =
new (ctx) DeclRefExpr(bufferDecl, SourceLoc(), IsImplicit);
Expr *value = buildBuiltinTake(ctx, bufferRef,
getTypeOfStorage(storage, TC));
Expr *storageRef =
buildStorageReference(
CallbackStorageReferenceContext{selfDecl, callbackStorageDecl},
storage, semantics,
SelfAccessKind::Peer, TC);
body.push_back(new (ctx) AssignExpr(storageRef, SourceLoc(),
value, IsImplicit));
// If this is a subscript, deallocate the subscript buffer:
if (auto subscript = dyn_cast<SubscriptDecl>(storage)) {
// Builtin.deallocValueBuffer(&callbackStorage, IndexType.self)
body.push_back(buildValueBufferOperation(ctx, "deallocValueBuffer",
callbackStorageDecl,
subscript->getIndicesType()));
}
});
// return (buffer, callback)
Expr *result = new (ctx) DeclRefExpr(bufferDecl, SourceLoc(), IsImplicit);
result = buildMaterializeForSetResult(ctx, result, callback);
body.push_back(new (ctx) ReturnStmt(SourceLoc(), result, IsImplicit));
SourceLoc loc = storage->getLoc();
materializeForSet->setBody(BraceStmt::create(ctx, loc, body, loc, true));
// Mark it transparent, there is no user benefit to this actually existing.
materializeForSet->getAttrs().add(new (ctx) TransparentAttr(IsImplicit));
TC.typeCheckDecl(materializeForSet, true);
// Register the accessor as an external decl if the storage was imported.
if (needsToBeRegisteredAsExternalDecl(storage))
TC.Context.addedExternalDecl(materializeForSet);
}
/// Build a direct call to an addressor from within a
/// materializeForSet method.
static Expr *buildCallToAddressor(FuncDecl *materializeForSet,
AbstractStorageDecl *storage,
VarDecl *bufferDecl,
FuncDecl *addressor,
ASTContext &ctx) {
// Build a direct reference to the addressor.
Expr *fn;
// Apply the self argument if applicable.
if (auto self = materializeForSet->getImplicitSelfDecl()) {
Expr *selfRef = new (ctx) DeclRefExpr(self, SourceLoc(), IsImplicit);
// if (addressor->computeSelfType(nullptr)->is<LValueType>()) {
// selfRef = new (ctx) InOutExpr(SourceLoc(), selfRef, Type(), IsImplicit);
// }
ValueDecl *localMembers[] = { addressor };
fn = new (ctx) OverloadedMemberRefExpr(selfRef, SourceLoc(),
ctx.AllocateCopy(localMembers),
SourceLoc(), IsImplicit, Type(),
AccessSemantics::DirectToStorage);
} else {
fn = new (ctx) DeclRefExpr(addressor, SourceLoc(), IsImplicit,
AccessSemantics::DirectToStorage);
}
// Apply the rest of the addressor arguments.
Expr *args;
if (isa<SubscriptDecl>(storage)) {
args = buildSubscriptIndexReference(ctx, materializeForSet);
} else {
args = TupleExpr::createImplicit(ctx, {}, {});
}
return new (ctx) CallExpr(fn, args, IsImplicit);
}
/// Given an expression of type UnsafeMutablePointer<T>, create an
/// expression of type Builtin.RawPointer.
static Expr *buildUnsafeMutablePointerToRawPointer(Expr *operand,
ASTContext &ctx) {
// Just directly drill in.
NominalTypeDecl *ptrType = ctx.getUnsafeMutablePointerDecl();
// If that doesn't work, just bail out; the result probably won't
// type-check, but there are worse failure modes for a broken stdlib.
if (!ptrType) return operand;
auto props = ptrType->getStoredProperties();
if (props.begin() == props.end()) return operand;
auto storageProp = props.front();
return new (ctx) MemberRefExpr(operand, SourceLoc(), storageProp,
SourceRange(), IsImplicit);
}
/// Synthesize the body of a materializeForSet accessor for an
/// addressed property.
static void synthesizeAddressedMaterializeForSet(FuncDecl *materializeForSet,
AbstractStorageDecl *storage,
VarDecl *bufferDecl,
TypeChecker &TC) {
ASTContext &ctx = TC.Context;
SmallVector<ASTNode, 4> body;
// Call the mutable addressor.
auto addressor = storage->getMutableAddressor();
Expr *addressorResult = buildCallToAddressor(materializeForSet, storage,
bufferDecl, addressor, ctx);
Expr *result;
Expr *callback;
switch (addressor->getAddressorKind()) {
case AddressorKind::NotAddressor:
llvm_unreachable("addressor is not an addressor?");
// If we have an unsafe addressor, this is easy: we just pull out
// the raw pointer and use that as the result.
case AddressorKind::Unsafe:
result = buildUnsafeMutablePointerToRawPointer(addressorResult, ctx);
callback = nullptr;
break;
case AddressorKind::Owning:
case AddressorKind::NativeOwning:
case AddressorKind::NativePinning: {
// We need to bind the result to a temporary variable.
// let temporary = addressor(self)(indices)
auto tempDecl = new (ctx) VarDecl(/*static*/ false, /*let*/ true,
SourceLoc(), ctx.getIdentifier("tmp"),
Type(), materializeForSet);
tempDecl->setImplicit(IsImplicit);
auto bindingPattern = new (ctx) NamedPattern(tempDecl, IsImplicit);
auto bindingDecl = PatternBindingDecl::create(ctx, /*static*/ SourceLoc(),
StaticSpellingKind::None,
SourceLoc(), bindingPattern,
addressorResult,
materializeForSet);
bindingDecl->setImplicit(IsImplicit);
body.push_back(bindingDecl);
body.push_back(tempDecl);
// This should be Builtin.NativePointer or something like it.
Type ownerType = [&]() -> Type {
switch (addressor->getAddressorKind()){
case AddressorKind::NotAddressor:
case AddressorKind::Unsafe:
llvm_unreachable("filtered out");
case AddressorKind::Owning:
return ctx.TheUnknownObjectType;
case AddressorKind::NativeOwning:
return ctx.TheNativeObjectType;
case AddressorKind::NativePinning:
return OptionalType::get(ctx.TheNativeObjectType);
}
llvm_unreachable("bad addressor kind");
}();
// Initialize the callback storage with the owner value, which is
// the second element of the addressor result.
Expr *owner = new (ctx) DeclRefExpr(tempDecl, SourceLoc(), IsImplicit);
owner = new (ctx) TupleElementExpr(owner, SourceLoc(), /*field index*/ 1,
SourceLoc(), Type());
owner->setImplicit(IsImplicit);
body.push_back(buildInitializeCallbackStorage(materializeForSet, owner,
ownerType, ctx));
// The result is the first element of the addressor result.
result = new (ctx) DeclRefExpr(tempDecl, SourceLoc(), IsImplicit);
result = new (ctx) TupleElementExpr(result, SourceLoc(), /*field index*/ 0,
SourceLoc(), Type());
result->setImplicit(IsImplicit);
result = buildUnsafeMutablePointerToRawPointer(result, ctx);
// Build the callback.
callback = buildMaterializeForSetCallback(ctx, materializeForSet, storage,
[&](SmallVectorImpl<ASTNode> &body, VarDecl *selfDecl,
VarDecl *bufferDecl, VarDecl *callbackStorageDecl) {
// Pull the owner out of callback storage.
Expr *owner =
buildTakeFromCallbackStorage(callbackStorageDecl, ownerType, ctx);
// For an owning addressor, we can just drop the value we pulled out.
if (addressor->getAddressorKind() != AddressorKind::NativePinning) {
body.push_back(owner);
// For a pinning addressor, we have to unpin it.
} else {
Expr *unpin = buildCallToBuiltin(ctx, "unpin", { owner });
body.push_back(unpin);
}
// This should always be a no-op, but do it for the sake of formalism.
// Builtin.deallocValueBuffer(&callbackStorage, OwnerType.self)
body.push_back(buildValueBufferOperation(ctx, "deallocValueBuffer",
callbackStorageDecl,
ownerType));
});
break;
}
}
// return (buffer, callback)
result = buildMaterializeForSetResult(ctx, result, callback);
body.push_back(new (ctx) ReturnStmt(SourceLoc(), result, IsImplicit));
SourceLoc loc = storage->getLoc();
materializeForSet->setBody(BraceStmt::create(ctx, loc, body, loc));
// Mark it transparent, there is no user benefit to this actually existing.
materializeForSet->getAttrs().add(new (ctx) TransparentAttr(IsImplicit));
TC.typeCheckDecl(materializeForSet, true);
// Register the accessor as an external decl if the storage was imported.
if (needsToBeRegisteredAsExternalDecl(storage))
TC.Context.addedExternalDecl(materializeForSet);
}
void swift::synthesizeMaterializeForSet(FuncDecl *materializeForSet,
AbstractStorageDecl *storage,
TypeChecker &TC) {
VarDecl *bufferDecl = getFirstParamDecl(materializeForSet);
switch (storage->getStorageKind()) {
case AbstractStorageDecl::Stored:
case AbstractStorageDecl::Addressed:
llvm_unreachable("no accessors");
// We can use direct access to stored variables, but not if they're
// weak, unowned, or dynamic.
case AbstractStorageDecl::StoredWithTrivialAccessors: {
// Only variables can be Stored, and only variables can be weak/unowned.
auto var = cast<VarDecl>(storage);
if (var->getType()->is<ReferenceStorageType>()
|| needsDynamicMaterializeForSet(var)) {
synthesizeComputedMaterializeForSet(materializeForSet, storage,
bufferDecl, TC);
return;
}
synthesizeStoredMaterializeForSet(materializeForSet, storage,
bufferDecl, TC);
return;
}
// We should access these by calling mutableAddress.
case AbstractStorageDecl::AddressedWithTrivialAccessors:
case AbstractStorageDecl::ComputedWithMutableAddress:
synthesizeAddressedMaterializeForSet(materializeForSet, storage,
bufferDecl, TC);
return;
// These must be accessed with a getter/setter pair.
// TODO: StoredWithObservers and AddressedWithObservers could be
// made to work with the callback as long as there isn't a willSet.
case AbstractStorageDecl::StoredWithObservers:
case AbstractStorageDecl::InheritedWithObservers:
case AbstractStorageDecl::AddressedWithObservers:
case AbstractStorageDecl::Computed:
synthesizeComputedMaterializeForSet(materializeForSet, storage,
bufferDecl, TC);
return;
}
llvm_unreachable("bad abstract storage kind");
}
/// 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);
// 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 = nullptr;
Set->getBodyParamPatterns().back()->forEachVariable([&](VarDecl *VD) {
assert(!ValueDecl && "Already found 'value'?");
ValueDecl = VD;
});
// 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, /*isLet*/ true,
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, SourceLoc(), /*imp*/true);
auto *ValueDRE = new (Ctx) DeclRefExpr(ValueDecl, SourceLoc(), /*imp*/true);
if (SelfDecl) {
auto *SelfDRE = new (Ctx) DeclRefExpr(SelfDecl, SourceLoc(), /*imp*/true);
Callee = new (Ctx) DotSyntaxCallExpr(Callee, SourceLoc(), SelfDRE);
}
SetterBody.push_back(new (Ctx) CallExpr(Callee, ValueDRE, true));
// Make sure the didSet/willSet accessors are marked final if in a class.
if (!willSet->isFinal() &&
VD->getDeclContext()->isClassOrClassExtensionContext())
makeFinal(Ctx, willSet);
}
// Create an assignment into the storage or call to superclass setter.
auto *ValueDRE = new (Ctx) DeclRefExpr(ValueDecl, SourceLoc(), 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, SourceLoc(),
/*impl*/true);
Expr *Callee = new (Ctx) DeclRefExpr(didSet, SourceLoc(), /*imp*/true);
if (SelfDecl) {
auto *SelfDRE = new (Ctx) DeclRefExpr(SelfDecl, SourceLoc(), /*imp*/true);
Callee = new (Ctx) DotSyntaxCallExpr(Callee, SourceLoc(), SelfDRE);
}
SetterBody.push_back(new (Ctx) CallExpr(Callee, OldValueExpr, true));
// Make sure the didSet/willSet accessors are marked final if in a class.
if (!didSet->isFinal() &&
VD->getDeclContext()->isClassOrClassExtensionContext())
makeFinal(Ctx, didSet);
}
Set->setBody(BraceStmt::create(Ctx, Loc, SetterBody, Loc, true));
// Type check the body of the getter and setter.
TC.typeCheckDecl(Get, true);
TC.typeCheckDecl(Get, false);
TC.typeCheckDecl(Set, true);
TC.typeCheckDecl(Set, false);
}
static void convertNSManagedStoredVarToComputed(VarDecl *VD, TypeChecker &TC) {
assert(VD->getStorageKind() == AbstractStorageDecl::Stored);
// Create the getter.
auto *Get = createGetterPrototype(VD, TC);
// Create the setter.
VarDecl *SetValueDecl = nullptr;
auto *Set = createSetterPrototype(VD, SetValueDecl, TC);
// Okay, we have both the getter and setter. Set them in VD.
VD->makeComputed(VD->getLoc(), Get, Set, nullptr, VD->getLoc());
TC.validateDecl(Get);
TC.validateDecl(Set);
// We've added some members to our containing class/extension, add them to
// the members list.
addMemberToContextIfNeeded(Get, VD->getDeclContext());
addMemberToContextIfNeeded(Set, VD->getDeclContext());
}
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}; }
};
}
/// Synthesize the getter for an 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();
TC.validateDecl(Get);
SmallVector<ASTNode, 6> Body;
// Load the existing storage and store it into the 'tmp1' temporary.
auto *Tmp1VD = new (Ctx) VarDecl(/*isStatic*/false, /*isLet*/true,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, SourceLoc(), /*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, SourceLoc(), /*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, /*isLet*/true,
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, SourceLoc(), /*Implicit*/true,
AccessSemantics::DirectToStorage);
createPropertyStoreOrCallSuperclassSetter(Get, Tmp2DRE, Storage, Body, TC);
// Return tmp2.
Tmp2DRE = new (Ctx) DeclRefExpr(Tmp2VD, SourceLoc(), /*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::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 *Storage = new (Context) VarDecl(/*isStatic*/false, /*isLet*/false,
VD->getLoc(), StorageName, StorageTy,
VD->getDeclContext());
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());
// Now that we've got the storage squared away, synthesize the getter.
auto *Get = completeLazyPropertyGetter(VD, Storage, *this);
// The setter just forwards on to storage without materializing the initial
// value.
auto *Set = VD->getSetter();
validateDecl(Set);
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()->isClassOrClassExtensionContext())
makeFinal(Context, Storage);
Storage->setImplicit();
Storage->setAccessibility(Accessibility::Private);
Storage->setSetterAccessibility(Accessibility::Private);
typeCheckDecl(Get, true);
typeCheckDecl(Get, false);
typeCheckDecl(Set, true);
typeCheckDecl(Set, false);
}
/// 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;
// Don't bother if the declaration is invalid.
if (storage->isInvalid()) return;
// We only need materializeForSet in polymorphic contexts:
auto containerTy =
storage->getDeclContext()->getDeclaredTypeOfContext();
if (!containerTy) return;
NominalTypeDecl *container = containerTy->getAnyNominal();
assert(container && "extension of non-nominal type?");
// - in non-ObjC protocols, but not protocol extensions.
if (auto protocol = dyn_cast<ProtocolDecl>(container)) {
if (protocol->isObjC()) return;
if (storage->getDeclContext()->isProtocolExtensionContext()) return;
// - in classes when the storage decl is not final and does
// not override a decl that requires a materializeForSet
} else if (isa<ClassDecl>(container)) {
if (storage->isFinal()) {
auto overridden = storage->getOverriddenDecl();
if (!overridden || !overridden->getMaterializeForSetFunc())
return;
}
// Structs and enums don't need this.
} else {
assert(isa<StructDecl>(container) || isa<EnumDecl>(container));
return;
}
addMaterializeForSet(storage, TC);
}
void swift::maybeAddAccessorsToVariable(VarDecl *var, TypeChecker &TC) {
if (var->getGetter() || var->isBeingTypeChecked() || isa<ParamDecl>(var))
return;
// Lazy properties get accessors.
if (var->getAttrs().hasAttribute<LazyAttr>()) {
var->setIsBeingTypeChecked();
auto *getter = createGetterPrototype(var, TC);
// lazy getters are mutating on an enclosing value type.
if (!var->getDeclContext()->isClassOrClassExtensionContext())
getter->setMutating();
getter->setAccessibility(var->getFormalAccess());
VarDecl *newValueParam = nullptr;
auto *setter = createSetterPrototype(var, newValueParam, TC);
var->makeComputed(var->getLoc(), getter, setter, nullptr,
var->getLoc());
var->setIsBeingTypeChecked(false);
TC.validateDecl(getter);
TC.validateDecl(setter);
addMemberToContextIfNeeded(getter, var->getDeclContext());
addMemberToContextIfNeeded(setter, var->getDeclContext());
return;
}
// Stored properties in SIL mode don't get auto-synthesized accessors.
bool isInSILMode = false;
if (auto sourceFile = var->getDeclContext()->getParentSourceFile())
isInSILMode = sourceFile->Kind == SourceFileKind::SIL;
auto nominal = var->getDeclContext()->isNominalTypeOrNominalTypeExtensionContext();
if (var->hasAccessorFunctions() ||
var->isImplicit() ||
nominal == nullptr)
return;
// Non-NSManaged class instance variables get accessors, because it affects
// vtable layout.
if (isa<ClassDecl>(nominal)) {
if (var->getAttrs().hasAttribute<NSManagedAttr>()) {
var->setIsBeingTypeChecked();
convertNSManagedStoredVarToComputed(var, TC);
var->setIsBeingTypeChecked(false);
} else if (!isInSILMode) {
var->setIsBeingTypeChecked();
addTrivialAccessorsToStorage(var, TC);
var->setIsBeingTypeChecked(false);
}
}
// Public instance variables of resilient structs get accessors.
if (auto structDecl = dyn_cast<StructDecl>(nominal)) {
if (!structDecl->hasFixedLayout() && !isInSILMode) {
var->setIsBeingTypeChecked();
addTrivialAccessorsToStorage(var, TC);
var->setIsBeingTypeChecked(false);
}
}
}
/// \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();
Accessibility accessLevel = decl->getFormalAccess();
if (!decl->hasClangNode())
accessLevel = std::min(accessLevel, Accessibility::Internal);
// Determine the parameter type of the implicit constructor.
SmallVector<TuplePatternElt, 8> patternElts;
SmallVector<Identifier, 8> argNames;
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 = tc.getTypeOfRValue(var);
// 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);
// Create the parameter.
auto *arg = new (context) ParamDecl(/*IsLet*/true, Loc, var->getName(),
Loc, var->getName(), varType, decl);
arg->setImplicit();
argNames.push_back(var->getName());
Pattern *pattern = new (context) NamedPattern(arg);
pattern->setImplicit();
TypeLoc tyLoc = TypeLoc::withoutLoc(varType);
pattern = new (context) TypedPattern(pattern, tyLoc);
patternElts.push_back(TuplePatternElt(var->getName(), SourceLoc(),
pattern, false));
}
}
auto pattern = TuplePattern::create(context, Loc, patternElts, Loc);
pattern->setImplicit();
// Create the constructor.
DeclName name(context, context.Id_init, argNames);
Pattern *selfPat = buildImplicitSelfParameter(Loc, decl);
auto *ctor = new (context) ConstructorDecl(name, Loc, OTK_None, SourceLoc(),
selfPat, pattern,
nullptr, SourceLoc(), decl);
// Mark implicit.
ctor->setImplicit();
ctor->setAccessibility(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(/*implicit=*/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.addedExternalDecl(ctor);
}
return ctor;
}
/// Create an expression that references the variables in the given
/// pattern for, e.g., forwarding of these variables to another
/// function with the same signature.
static Expr *forwardArguments(TypeChecker &tc, ClassDecl *classDecl,
ConstructorDecl *toDecl,
Pattern *bodyPattern,
ArrayRef<Identifier> argumentNames) {
switch (bodyPattern->getKind()) {
#define PATTERN(Id, Parent)
#define REFUTABLE_PATTERN(Id, Parent) case PatternKind::Id:
#include "swift/AST/PatternNodes.def"
return nullptr;
case PatternKind::Paren: {
auto subExpr = forwardArguments(tc, classDecl, toDecl,
cast<ParenPattern>(bodyPattern)->getSubPattern(),
{ });
if (!subExpr) return nullptr;
// If there is a name for this single-argument thing, then form a tupleexpr.
if (argumentNames.size() != 1 || argumentNames[0].empty())
return new (tc.Context) ParenExpr(SourceLoc(), subExpr, SourceLoc(),
/*hasTrailingClosure=*/false);
return TupleExpr::createImplicit(tc.Context, subExpr, argumentNames);
}
case PatternKind::Tuple: {
auto bodyTuple = cast<TuplePattern>(bodyPattern);
SmallVector<Expr *, 4> values;
// FIXME: Can't forward varargs yet.
if (bodyTuple->hasAnyEllipsis()) {
tc.diagnose(classDecl->getLoc(),
diag::unsupported_synthesize_init_variadic,
classDecl->getDeclaredType());
tc.diagnose(toDecl, diag::variadic_superclass_init_here);
return nullptr;
}
for (unsigned i = 0, n = bodyTuple->getNumElements(); i != n; ++i) {
// Forward the value.
auto subExpr = forwardArguments(tc, classDecl, toDecl,
bodyTuple->getElement(i).getPattern(),
{ });
if (!subExpr)
return nullptr;
values.push_back(subExpr);
// Dig out the name.
auto subPattern = bodyTuple->getElement(i).getPattern();
do {
if (auto typed = dyn_cast<TypedPattern>(subPattern)) {
subPattern = typed->getSubPattern();
continue;
}
if (auto paren = dyn_cast<ParenPattern>(subPattern)) {
subPattern = paren->getSubPattern();
continue;
}
break;
} while (true);
}
if (values.size() == 1 &&
(argumentNames.empty() || argumentNames[0].empty()))
return new (tc.Context) ParenExpr(SourceLoc(), values[0], SourceLoc(),
/*hasTrailingClosure=*/false);
return TupleExpr::createImplicit(tc.Context, values, argumentNames);
}
case PatternKind::Any:
case PatternKind::Named: {
auto decl = cast<NamedPattern>(bodyPattern)->getDecl();
Expr *declRef = new (tc.Context) DeclRefExpr(decl, SourceLoc(),
/*Implicit=*/true);
if (decl->getType()->is<InOutType>())
declRef = new (tc.Context) InOutExpr(SourceLoc(), declRef,
Type(), /*isImplicit=*/true);
return declRef;
}
case PatternKind::Typed:
return forwardArguments(tc, classDecl, toDecl,
cast<TypedPattern>(bodyPattern)->getSubPattern(),
argumentNames);
case PatternKind::Var:
return forwardArguments(tc, classDecl, toDecl,
cast<VarPattern>(bodyPattern)->getSubPattern(),
argumentNames);
}
}
/// 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->getExtensionType()->getClassOrBoundGenericClass();
if (!unimplementedInitDecl) {
tc.diagnose(classDecl->getLoc(), diag::missing_unimplemented_init_runtime);
return;
}
// Create a call to Swift._unimplemented_initializer
auto loc = classDecl->getLoc();
Expr *fn = new (tc.Context) DeclRefExpr(unimplementedInitDecl, 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);
className = new (tc.Context) ParenExpr(loc, className, loc, false);
Expr *call = new (tc.Context) CallExpr(fn, className, /*Implicit=*/true);
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) {
// Determine the initializer parameters.
Type superInitType = superclassCtor->getInitializerInterfaceType();
if (superInitType->is<GenericFunctionType>() ||
classDecl->getGenericParamsOfContext()) {
// FIXME: Handle generic initializers as well.
return nullptr;
}
auto &ctx = tc.Context;
// Create the 'self' declaration and patterns.
auto *selfDecl = new (ctx) ParamDecl(/*IsLet*/ true,
SourceLoc(), Identifier(),
SourceLoc(), ctx.Id_self,
Type(), classDecl);
selfDecl->setImplicit();
Pattern *selfBodyPattern
= new (ctx) NamedPattern(selfDecl, /*Implicit=*/true);
selfBodyPattern = new (ctx) TypedPattern(selfBodyPattern, TypeLoc());
// Create the initializer parameter patterns.
OptionSet<Pattern::CloneFlags> options = Pattern::Implicit;
options |= Pattern::Inherited;
Pattern *bodyParamPatterns
= superclassCtor->getBodyParamPatterns()[1]->clone(ctx, options);
// Fix up the default arguments in the type to refer to inherited default
// arguments.
// FIXME: If we weren't cloning the type along with the pattern, this would be
// a lot more direct.
Type argType = bodyParamPatterns->getType();
// Local function that maps default arguments to inherited default arguments.
std::function<Type(Type)> inheritDefaultArgs = [&](Type type) -> Type {
auto tuple = type->getAs<TupleType>();
if (!tuple)
return type;
bool anyChanged = false;
SmallVector<TupleTypeElt, 4> elements;
unsigned index = 0;
for (const auto &elt : tuple->getElements()) {
Type eltTy = elt.getType().transform(inheritDefaultArgs);
if (!eltTy)
return Type();
// If nothing has changed, just keep going.
if (!anyChanged && eltTy.getPointer() == elt.getType().getPointer() &&
(elt.getDefaultArgKind() == DefaultArgumentKind::None ||
elt.getDefaultArgKind() == DefaultArgumentKind::Inherited)) {
++index;
continue;
}
// If this is the first change we've seen, copy all of the previous
// elements.
if (!anyChanged) {
// Copy all of the previous elements.
for (unsigned i = 0; i != index; ++i) {
const TupleTypeElt &FromElt = tuple->getElement(i);
elements.push_back(TupleTypeElt(FromElt.getType(), FromElt.getName(),
FromElt.getDefaultArgKind(),
FromElt.isVararg()));
}
anyChanged = true;
}
// Add the new tuple element, with the new type, no initializer,
auto defaultArgKind = elt.getDefaultArgKind();
if (defaultArgKind != DefaultArgumentKind::None)
defaultArgKind = DefaultArgumentKind::Inherited;
elements.push_back(TupleTypeElt(eltTy, elt.getName(), defaultArgKind,
elt.isVararg()));
++index;
}
if (!anyChanged)
return type;
return TupleType::get(elements, ctx);
};
argType = argType.transform(inheritDefaultArgs);
bodyParamPatterns->setType(argType);
// Create the initializer declaration.
auto ctor = new (ctx) ConstructorDecl(superclassCtor->getFullName(),
classDecl->getBraces().Start,
superclassCtor->getFailability(),
SourceLoc(),
selfBodyPattern, bodyParamPatterns,
nullptr, SourceLoc(), classDecl);
ctor->setImplicit();
ctor->setAccessibility(std::min(classDecl->getFormalAccess(),
superclassCtor->getFormalAccess()));
// Make sure the constructor is only as available as its superclass's
// constructor.
AvailabilityInference::applyInferredAvailableAttrs(ctor, superclassCtor,
ctx);
// Configure 'self'.
Type selfType = configureImplicitSelf(tc, ctor);
selfBodyPattern->setType(selfType);
cast<TypedPattern>(selfBodyPattern)->getSubPattern()->setType(selfType);
// Set the type of the initializer.
configureConstructorType(ctor, selfType,
bodyParamPatterns->getType(),
superclassCtor->isBodyThrowing());
if (superclassCtor->isObjC()) {
auto errorConvention = superclassCtor->getForeignErrorConvention();
markAsObjC(tc, ctor, ObjCReason::ImplicitlyObjC, errorConvention);
// 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);
// Set it to implicit to disable printing it for SIL.
clonedAttr->setImplicit(true);
ctor->getAttrs().add(clonedAttr);
}
}
}
if (superclassCtor->isRequired())
ctor->getAttrs().add(new (tc.Context) RequiredAttr(/*implicit=*/true));
// Wire up the overrides.
ctor->getAttrs().add(new (tc.Context) OverrideAttr(/*Implicit=*/true));
checkOverrides(tc, ctor);
if (kind == DesignatedInitKind::Stub) {
// Make this a stub implementation.
createStubBody(tc, ctor);
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) UnresolvedConstructorExpr(superRef,
SourceLoc(),
SourceLoc(),
/*Implicit=*/true);
Expr *ctorArgs = forwardArguments(tc, classDecl, superclassCtor,
ctor->getBodyParamPatterns()[1],
ctor->getFullName().getArgumentNames());
if (!ctorArgs) {
// FIXME: We should be able to assert that this never happens,
// but there are currently holes when dealing with vararg
// initializers and _ parameters. Fail somewhat gracefully by
// generating a stub here.
createStubBody(tc, ctor);
return ctor;
}
Expr *superCall = new (ctx) CallExpr(ctorRef, ctorArgs, /*Implicit=*/true);
if (superclassCtor->isBodyThrowing()) {
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;
Pattern *selfPat = buildImplicitSelfParameter(CD->getLoc(), CD);
auto *DD = new (Context) DestructorDecl(Context.Id_deinit, CD->getLoc(),
selfPat, 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();
}