bool DeclContext::lookupQualified(Type type,
DeclName member,
NLOptions options,
LazyResolver *typeResolver,
SmallVectorImpl<ValueDecl *> &decls) const {
using namespace namelookup;
assert(decls.empty() && "additive lookup not supported");
if (type->is<ErrorType>())
return false;
auto checkLookupCascading = [this, options]() -> Optional<bool> {
switch (static_cast<unsigned>(options & NL_KnownDependencyMask)) {
case 0:
return isCascadingContextForLookup(/*excludeFunctions=*/false);
case NL_KnownNonCascadingDependency:
return false;
case NL_KnownCascadingDependency:
return true;
case NL_KnownNoDependency:
return None;
default:
// FIXME: Use llvm::CountPopulation_64 when that's declared constexpr.
static_assert(__builtin_popcountll(NL_KnownDependencyMask) == 2,
"mask should only include four values");
llvm_unreachable("mask only includes four values");
}
};
// Look through lvalue and inout types.
type = type->getLValueOrInOutObjectType();
// Look through metatypes.
if (auto metaTy = type->getAs<AnyMetatypeType>())
type = metaTy->getInstanceType();
// Look through DynamicSelf.
if (auto dynamicSelf = type->getAs<DynamicSelfType>())
type = dynamicSelf->getSelfType();
// Look for module references.
if (auto moduleTy = type->getAs<ModuleType>()) {
Module *module = moduleTy->getModule();
auto topLevelScope = getModuleScopeContext();
if (module == topLevelScope->getParentModule()) {
if (auto maybeLookupCascade = checkLookupCascading()) {
recordLookupOfTopLevelName(topLevelScope, member,
maybeLookupCascade.getValue());
}
lookupInModule(module, /*accessPath=*/{}, member, decls,
NLKind::QualifiedLookup, ResolutionKind::Overloadable,
typeResolver, topLevelScope);
} else {
// Note: This is a lookup into another module. Unless we're compiling
// multiple modules at once, or if the other module re-exports this one,
// it shouldn't be possible to have a dependency from that module on
// anything in this one.
// Perform the lookup in all imports of this module.
forAllVisibleModules(this,
[&](const Module::ImportedModule &import) -> bool {
if (import.second != module)
return true;
lookupInModule(import.second, import.first, member, decls,
NLKind::QualifiedLookup, ResolutionKind::Overloadable,
typeResolver, topLevelScope);
// If we're able to do an unscoped lookup, we see everything. No need
// to keep going.
return !import.first.empty();
});
}
llvm::SmallPtrSet<ValueDecl *, 4> knownDecls;
decls.erase(std::remove_if(decls.begin(), decls.end(),
[&](ValueDecl *vd) -> bool {
// If we're performing a type lookup, don't even attempt to validate
// the decl if its not a type.
if ((options & NL_OnlyTypes) && !isa<TypeDecl>(vd))
return true;
return !knownDecls.insert(vd).second;
}), decls.end());
if (auto *debugClient = topLevelScope->getParentModule()->getDebugClient())
filterForDiscriminator(decls, debugClient);
return !decls.empty();
}
auto &ctx = getASTContext();
if (!ctx.LangOpts.EnableAccessControl)
options |= NL_IgnoreAccessibility;
// The set of nominal type declarations we should (and have) visited.
SmallVector<NominalTypeDecl *, 4> stack;
llvm::SmallPtrSet<NominalTypeDecl *, 4> visited;
// Handle nominal types.
bool wantProtocolMembers = false;
bool wantLookupInAllClasses = false;
if (auto nominal = type->getAnyNominal()) {
visited.insert(nominal);
stack.push_back(nominal);
wantProtocolMembers = (options & NL_ProtocolMembers) &&
!isa<ProtocolDecl>(nominal);
// If we want dynamic lookup and we're searching in the
// AnyObject protocol, note this for later.
if (options & NL_DynamicLookup) {
if (auto proto = dyn_cast<ProtocolDecl>(nominal)) {
if (proto->isSpecificProtocol(KnownProtocolKind::AnyObject))
wantLookupInAllClasses = true;
}
}
}
// Handle archetypes
else if (auto archetypeTy = type->getAs<ArchetypeType>()) {
// Look in the protocols to which the archetype conforms (always).
for (auto proto : archetypeTy->getConformsTo())
if (visited.insert(proto).second)
stack.push_back(proto);
// If requested, look into the superclasses of this archetype.
if (options & NL_VisitSupertypes) {
if (auto superclassTy = archetypeTy->getSuperclass()) {
if (auto superclassDecl = superclassTy->getAnyNominal()) {
if (visited.insert(superclassDecl).second) {
stack.push_back(superclassDecl);
wantProtocolMembers = (options & NL_ProtocolMembers) &&
!isa<ProtocolDecl>(superclassDecl);
}
}
}
}
}
// Handle protocol compositions.
else if (auto compositionTy = type->getAs<ProtocolCompositionType>()) {
SmallVector<ProtocolDecl *, 4> protocols;
if (compositionTy->isExistentialType(protocols)) {
for (auto proto : protocols) {
if (visited.insert(proto).second) {
stack.push_back(proto);
// If we want dynamic lookup and this is the AnyObject
// protocol, note this for later.
if ((options & NL_DynamicLookup) &&
proto->isSpecificProtocol(KnownProtocolKind::AnyObject))
wantLookupInAllClasses = true;
}
}
}
}
// Allow filtering of the visible declarations based on various
// criteria.
bool onlyCompleteObjectInits = false;
auto isAcceptableDecl = [&](NominalTypeDecl *current, Decl *decl) -> bool {
// If the decl is currently being type checked, then we have something
// cyclic going on. Instead of poking at parts that are potentially not
// set up, just assume it is acceptable. This will make sure we produce an
// error later.
if (decl->isBeingTypeChecked())
return true;
// Filter out designated initializers, if requested.
if (onlyCompleteObjectInits) {
if (auto ctor = dyn_cast<ConstructorDecl>(decl)) {
if (!ctor->isInheritable())
return false;
} else {
return false;
}
}
// Ignore stub implementations.
if (auto ctor = dyn_cast<ConstructorDecl>(decl)) {
if (ctor->hasStubImplementation())
return false;
}
// Check access.
if (!(options & NL_IgnoreAccessibility))
if (auto VD = dyn_cast<ValueDecl>(decl))
return VD->isAccessibleFrom(this);
return true;
};
ReferencedNameTracker *tracker = nullptr;
if (auto containingSourceFile = dyn_cast<SourceFile>(getModuleScopeContext()))
tracker = containingSourceFile->getReferencedNameTracker();
bool isLookupCascading;
if (tracker) {
if (auto maybeLookupCascade = checkLookupCascading())
isLookupCascading = maybeLookupCascade.getValue();
else
tracker = nullptr;
}
// Visit all of the nominal types we know about, discovering any others
// we need along the way.
while (!stack.empty()) {
auto current = stack.back();
stack.pop_back();
if (tracker)
tracker->addUsedMember({current, member.getBaseName()},isLookupCascading);
// Make sure we've resolved implicit constructors, if we need them.
if (member.getBaseName() == ctx.Id_init && typeResolver)
typeResolver->resolveImplicitConstructors(current);
// Look for results within the current nominal type and its extensions.
bool currentIsProtocol = isa<ProtocolDecl>(current);
for (auto decl : current->lookupDirect(member)) {
// If we're performing a type lookup, don't even attempt to validate
// the decl if its not a type.
if ((options & NL_OnlyTypes) && !isa<TypeDecl>(decl))
continue;
// Resolve the declaration signature when we find the
// declaration.
if (typeResolver && !decl->isBeingTypeChecked()) {
typeResolver->resolveDeclSignature(decl);
if (!decl->hasType())
continue;
}
if (isAcceptableDecl(current, decl))
decls.push_back(decl);
}
// If we're not supposed to visit our supertypes, we're done.
if ((options & NL_VisitSupertypes) == 0)
continue;
// Visit superclass.
if (auto classDecl = dyn_cast<ClassDecl>(current)) {
// If we're looking for initializers, only look at the superclass if the
// current class permits inheritance. Even then, only find complete
// object initializers.
bool visitSuperclass = true;
if (member.getBaseName() == ctx.Id_init) {
if (classDecl->inheritsSuperclassInitializers(typeResolver))
onlyCompleteObjectInits = true;
else
visitSuperclass = false;
}
if (visitSuperclass) {
if (auto superclassType = classDecl->getSuperclass())
if (auto superclassDecl = superclassType->getClassOrBoundGenericClass())
if (visited.insert(superclassDecl).second)
stack.push_back(superclassDecl);
}
}
// If we're not looking at a protocol and we're not supposed to
// visit the protocols that this type conforms to, skip the next
// step.
if (!wantProtocolMembers && !currentIsProtocol)
continue;
SmallVector<ProtocolDecl *, 4> protocols;
for (auto proto : current->getAllProtocols()) {
if (visited.insert(proto).second) {
stack.push_back(proto);
}
}
// For a class, we don't need to visit the protocol members of the
// superclass: that's already handled.
if (isa<ClassDecl>(current))
wantProtocolMembers = false;
}
// If we want to perform lookup into all classes, do so now.
if (wantLookupInAllClasses) {
if (tracker)
tracker->addDynamicLookupName(member.getBaseName(), isLookupCascading);
// Collect all of the visible declarations.
SmallVector<ValueDecl *, 4> allDecls;
forAllVisibleModules(this, [&](Module::ImportedModule import) {
import.second->lookupClassMember(import.first, member, allDecls);
});
// For each declaration whose context is not something we've
// already visited above, add it to the list of declarations.
llvm::SmallPtrSet<ValueDecl *, 4> knownDecls;
for (auto decl : allDecls) {
// If we're performing a type lookup, don't even attempt to validate
// the decl if its not a type.
if ((options & NL_OnlyTypes) && !isa<TypeDecl>(decl))
continue;
if (typeResolver && !decl->isBeingTypeChecked()) {
typeResolver->resolveDeclSignature(decl);
if (!decl->hasType())
continue;
}
// If the declaration has an override, name lookup will also have
// found the overridden method. Skip this declaration, because we
// prefer the overridden method.
if (decl->getOverriddenDecl())
continue;
auto dc = decl->getDeclContext();
auto nominal = dyn_cast<NominalTypeDecl>(dc);
if (!nominal) {
auto ext = cast<ExtensionDecl>(dc);
nominal = ext->getExtendedType()->getAnyNominal();
assert(nominal && "Couldn't find nominal type?");
}
// If we didn't visit this nominal type above, add this
// declaration to the list.
if (!visited.count(nominal) && knownDecls.insert(decl).second &&
isAcceptableDecl(nominal, decl))
decls.push_back(decl);
}
}
// If we're supposed to remove overridden declarations, do so now.
if (options & NL_RemoveOverridden)
removeOverriddenDecls(decls);
// If we're supposed to remove shadowed/hidden declarations, do so now.
Module *M = getParentModule();
if (options & NL_RemoveNonVisible)
removeShadowedDecls(decls, M, typeResolver);
if (auto *debugClient = M->getDebugClient())
filterForDiscriminator(decls, debugClient);
// We're done. Report success/failure.
return !decls.empty();
}
