// Analyzing the body of this class destructor is valid because the object is
// dead. This means that the object is never passed to objc_setAssociatedObject,
// so its destructor cannot be extended at runtime.
static SILFunction *getDestructor(AllocRefInst *ARI) {
// We only support classes.
ClassDecl *ClsDecl = ARI->getType().getClassOrBoundGenericClass();
if (!ClsDecl)
return nullptr;
// Look up the destructor of ClsDecl.
DestructorDecl *Destructor = ClsDecl->getDestructor();
assert(Destructor && "getDestructor() should never return a nullptr.");
// Find the destructor name via SILDeclRef.
// FIXME: When destructors get moved into vtables, update this to use the
// vtable for the class.
SILDeclRef Ref(Destructor);
SILFunction *Fn = ARI->getModule().lookUpFunction(Ref);
if (!Fn || Fn->empty()) {
DEBUG(llvm::dbgs() << " Could not find destructor.\n");
return nullptr;
}
DEBUG(llvm::dbgs() << " Found destructor!\n");
// If the destructor has an objc_method calling convention, we cannot
// analyze it since it could be swapped out from under us at runtime.
if (Fn->getRepresentation() == SILFunctionTypeRepresentation::ObjCMethod) {
DEBUG(llvm::dbgs() << " Found objective-c destructor. Can't "
"analyze!\n");
return nullptr;
}
return Fn;
}
void SILGenFunction::emitDestroyingDestructor(DestructorDecl *dd) {
MagicFunctionName = DeclName(SGM.M.getASTContext().getIdentifier("deinit"));
RegularLocation Loc(dd);
if (dd->isImplicit())
Loc.markAutoGenerated();
auto cd = cast<ClassDecl>(dd->getDeclContext());
SILValue selfValue = emitSelfDecl(dd->getImplicitSelfDecl());
// Create a basic block to jump to for the implicit destruction behavior
// of releasing the elements and calling the superclass destructor.
// We won't actually emit the block until we finish with the destructor body.
prepareEpilog(Type(), false, CleanupLocation::get(Loc));
emitProfilerIncrement(dd->getBody());
// Emit the destructor body.
emitStmt(dd->getBody());
Optional<SILValue> maybeReturnValue;
SILLocation returnLoc(Loc);
std::tie(maybeReturnValue, returnLoc) = emitEpilogBB(Loc);
if (!maybeReturnValue)
return;
auto cleanupLoc = CleanupLocation::get(Loc);
// If we have a superclass, invoke its destructor.
SILValue resultSelfValue;
SILType objectPtrTy = SILType::getNativeObjectType(F.getASTContext());
if (cd->hasSuperclass()) {
Type superclassTy
= ArchetypeBuilder::mapTypeIntoContext(dd, cd->getSuperclass());
ClassDecl *superclass = superclassTy->getClassOrBoundGenericClass();
auto superclassDtorDecl = superclass->getDestructor();
SILDeclRef dtorConstant =
SILDeclRef(superclassDtorDecl, SILDeclRef::Kind::Destroyer);
SILType baseSILTy = getLoweredLoadableType(superclassTy);
SILValue baseSelf = B.createUpcast(cleanupLoc, selfValue, baseSILTy);
ManagedValue dtorValue;
SILType dtorTy;
ArrayRef<Substitution> subs
= superclassTy->gatherAllSubstitutions(SGM.M.getSwiftModule(), nullptr);
std::tie(dtorValue, dtorTy, subs)
= emitSiblingMethodRef(cleanupLoc, baseSelf, dtorConstant, subs);
resultSelfValue = B.createApply(cleanupLoc, dtorValue.forward(*this),
dtorTy, objectPtrTy, subs, baseSelf);
} else {
resultSelfValue = B.createUncheckedRefCast(cleanupLoc, selfValue,
objectPtrTy);
}
// Release our members.
emitClassMemberDestruction(selfValue, cd, cleanupLoc);
B.createReturn(returnLoc, resultSelfValue);
}
void SILGenFunction::emitObjCDestructor(SILDeclRef dtor) {
auto dd = cast<DestructorDecl>(dtor.getDecl());
auto cd = cast<ClassDecl>(dd->getDeclContext());
MagicFunctionName = DeclName(SGM.M.getASTContext().getIdentifier("deinit"));
RegularLocation loc(dd);
if (dd->isImplicit())
loc.markAutoGenerated();
SILValue selfValue = emitSelfDecl(dd->getImplicitSelfDecl());
// Create a basic block to jump to for the implicit destruction behavior
// of releasing the elements and calling the superclass destructor.
// We won't actually emit the block until we finish with the destructor body.
prepareEpilog(Type(), false, CleanupLocation::get(loc));
// Emit the destructor body.
emitStmt(dd->getBody());
Optional<SILValue> maybeReturnValue;
SILLocation returnLoc(loc);
std::tie(maybeReturnValue, returnLoc) = emitEpilogBB(loc);
if (!maybeReturnValue)
return;
auto cleanupLoc = CleanupLocation::get(loc);
// Note: the ivar destroyer is responsible for destroying the
// instance variables before the object is actually deallocated.
// Form a reference to the superclass -dealloc.
Type superclassTy = dd->mapTypeIntoContext(cd->getSuperclass());
assert(superclassTy && "Emitting Objective-C -dealloc without superclass?");
ClassDecl *superclass = superclassTy->getClassOrBoundGenericClass();
auto superclassDtorDecl = superclass->getDestructor();
SILDeclRef superclassDtor(superclassDtorDecl,
SILDeclRef::Kind::Deallocator,
SILDeclRef::ConstructAtBestResilienceExpansion,
SILDeclRef::ConstructAtNaturalUncurryLevel,
/*isForeign=*/true);
auto superclassDtorType = SGM.getConstantType(superclassDtor);
SILValue superclassDtorValue = B.createSuperMethod(
cleanupLoc, selfValue, superclassDtor,
superclassDtorType);
// Call the superclass's -dealloc.
SILType superclassSILTy = getLoweredLoadableType(superclassTy);
SILValue superSelf = B.createUpcast(cleanupLoc, selfValue, superclassSILTy);
ArrayRef<Substitution> subs
= superclassTy->gatherAllSubstitutions(SGM.M.getSwiftModule(), nullptr);
auto substDtorType = superclassDtorType.castTo<SILFunctionType>()
->substGenericArgs(SGM.M, subs);
SILFunctionConventions dtorConv(substDtorType, SGM.M);
B.createApply(cleanupLoc, superclassDtorValue,
SILType::getPrimitiveObjectType(substDtorType),
dtorConv.getSILResultType(), subs, superSelf);
// Return.
B.createReturn(returnLoc, emitEmptyTuple(cleanupLoc));
}
void SILGenFunction::emitObjCDestructor(SILDeclRef dtor) {
auto dd = cast<DestructorDecl>(dtor.getDecl());
auto cd = cast<ClassDecl>(dd->getDeclContext());
MagicFunctionName = DeclName(SGM.M.getASTContext().getIdentifier("deinit"));
RegularLocation loc(dd);
if (dd->isImplicit())
loc.markAutoGenerated();
SILValue selfValue = emitSelfDecl(dd->getImplicitSelfDecl());
// Create a basic block to jump to for the implicit destruction behavior
// of releasing the elements and calling the superclass destructor.
// We won't actually emit the block until we finish with the destructor body.
prepareEpilog(Type(), false, CleanupLocation::get(loc));
emitProfilerIncrement(dd->getBody());
// Emit the destructor body.
emitStmt(dd->getBody());
Optional<SILValue> maybeReturnValue;
SILLocation returnLoc(loc);
std::tie(maybeReturnValue, returnLoc) = emitEpilogBB(loc);
if (!maybeReturnValue)
return;
auto cleanupLoc = CleanupLocation::get(loc);
// Note: the ivar destroyer is responsible for destroying the
// instance variables before the object is actually deallocated.
// Form a reference to the superclass -dealloc.
Type superclassTy = dd->mapTypeIntoContext(cd->getSuperclass());
assert(superclassTy && "Emitting Objective-C -dealloc without superclass?");
ClassDecl *superclass = superclassTy->getClassOrBoundGenericClass();
auto superclassDtorDecl = superclass->getDestructor();
auto superclassDtor = SILDeclRef(superclassDtorDecl,
SILDeclRef::Kind::Deallocator)
.asForeign();
auto superclassDtorType = SGM.Types.getConstantType(superclassDtor);
SILValue superclassDtorValue = B.createObjCSuperMethod(
cleanupLoc, selfValue, superclassDtor,
superclassDtorType);
// Call the superclass's -dealloc.
SILType superclassSILTy = getLoweredLoadableType(superclassTy);
SILValue superSelf = B.createUpcast(cleanupLoc, selfValue, superclassSILTy);
assert(superSelf.getOwnershipKind() == ValueOwnershipKind::Owned);
auto subMap
= superclassTy->getContextSubstitutionMap(SGM.M.getSwiftModule(),
superclass);
auto substDtorType = superclassDtorType.substGenericArgs(SGM.M, subMap);
CanSILFunctionType substFnType = substDtorType.castTo<SILFunctionType>();
SILFunctionConventions dtorConv(substFnType, SGM.M);
assert(substFnType->getSelfParameter().getConvention() ==
ParameterConvention::Direct_Unowned &&
"Objective C deinitializing destructor takes self as unowned");
B.createApply(cleanupLoc, superclassDtorValue, substDtorType,
dtorConv.getSILResultType(), subMap, superSelf);
// We know that the givne value came in at +1, but we pass the relevant value
// as unowned to the destructor. Create a fake balance for the verifier to be
// happy.
B.createEndLifetime(cleanupLoc, superSelf);
// Return.
B.createReturn(returnLoc, emitEmptyTuple(cleanupLoc));
}