Refine Naive Dependency Collection Algorithm

Split off the notion of "recording" dependencies from the notion of
"collecting" dependencies. This corrects an oversight in the previous
design where dependency replay and recording were actually not "free" in
WMO where we actually never track dependencies. This architecture also
lays the groundwork for the removal of the referenced name trackers.

The algorithm builds upon the infrastructure for dependency sources and
sinks laid down during the cut over to request-based dependency tracking
in #30723.

The idea of the naive algorithm is this:

For a chain of requests A -> B* -> C -> D* -> ... -> L where L is a lookup
request and all starred requests are cached, once L writes into the
dependency collector, the active stack is walked and at each cache-point
the results of dependency collection are associated with the request
itself (in this example, B* and D* have all the names L found associated
with them). Subsequent evaluations of these cached requests (B* and D*
et al) will then *replay* the previous lookup results from L into the
active referenced name tracker. One complication is, suppose the
evaluation of a cached request involves multiple downstream name
lookups. More concretely, suppose we have the following request trace:

A* -> B -> L
      |
       -> C -> L
          |
           -> D -> L
              |
               -> ...

Then A* must see the union of the results of each L. If this reminds
anyone of a union-find, that is no accident! A persistent union-find
a la Conchon and Filliatre is probably in order to help bring down peak
heap usage...

include/swift/AST/Evaluator.h

@@ -225,7 +225,7 @@ class Evaluator {
   /// so all clients must cope with cycles.
   llvm::DenseMap<AnyRequest, std::vector<AnyRequest>> dependencies;
 
-  evaluator::DependencyCollector collector;
+  evaluator::DependencyRecorder recorder;
 
   /// Retrieve the request function for the given zone and request IDs.
   AbstractRequestFunction *getAbstractRequestFunction(uint8_t zoneID,
@@ -268,7 +268,7 @@ public:
            typename std::enable_if<Request::isEverCached>::type * = nullptr>
   llvm::Expected<typename Request::OutputType>
   operator()(const Request &request) {
-    evaluator::DependencyCollector::StackRAII<Request> incDeps{collector,
+    evaluator::DependencyRecorder::StackRAII<Request> incDeps{recorder,
                                                               request};
     // The request can be cached, but check a predicate to determine
     // whether this particular instance is cached. This allows more
@@ -285,7 +285,7 @@ public:
            typename std::enable_if<!Request::isEverCached>::type * = nullptr>
   llvm::Expected<typename Request::OutputType>
   operator()(const Request &request) {
-    evaluator::DependencyCollector::StackRAII<Request> incDeps{collector,
+    evaluator::DependencyRecorder::StackRAII<Request> incDeps{recorder,
                                                               request};
     return getResultUncached(request);
   }
@@ -436,7 +436,7 @@ private:
                                   !Request::isDependencySink>::type * = nullptr>
   void reportEvaluatedResult(const Request &r,
                              const typename Request::OutputType &o) {
-    collector.replay(ActiveRequest(r));
+    recorder.replay(ActiveRequest(r));
   }
 
   // Report the result of evaluating a request that is a dependency sink.
@@ -444,7 +444,7 @@ private:
             typename std::enable_if<Request::isDependencySink>::type * = nullptr>
   void reportEvaluatedResult(const Request &r,
                              const typename Request::OutputType &o) {
-    return collector.record(activeRequests, [&r, &o](auto &c) {
+    return recorder.record(activeRequests, [&r, &o](auto &c) {
       return r.writeDependencySink(c, o);
     });
   }

include/swift/AST/EvaluatorDependencies.h

@@ -107,13 +107,9 @@ inline DependencyScope getScopeForAccessLevel(AccessLevel l) {
 // of individual contexts.
 using DependencySource = llvm::PointerIntPair<SourceFile *, 1, DependencyScope>;
 
-/// A \c DependencyCollector is an aggregator of named references discovered in a
+struct DependencyRecorder;
-/// particular \c DependencyScope during the course of request evaluation.
-struct DependencyCollector {
-private:
-  /// A stack of dependency sources in the order they were evaluated.
-  llvm::SmallVector<evaluator::DependencySource, 8> dependencySources;
 
+struct DependencyCollector {
   struct Reference {
   public:
     enum class Kind {
@@ -178,36 +174,11 @@ private:
     };
   };
 
-public:
+  DependencyRecorder &parent;
-  enum class Mode {
-    // Enables the current "status quo" behavior of the dependency collector.
-    //
-    // By default, the dependency collector moves to register dependencies in
-    // the referenced name trackers at the top of the active dependency stack.
-    StatusQuo,
-    // Enables an experimental mode to only register private dependencies.
-    //
-    // This mode restricts the dependency collector to ignore changes of
-    // scope. This has practical effect of charging all unqualified lookups to
-    // the primary file being acted upon instead of to the destination file.
-    ExperimentalPrivateDependencies,
-  };
-  Mode mode;
-  llvm::DenseMap<AnyRequest, llvm::DenseSet<Reference, Reference::Info>>
-      requestReferences;
   llvm::DenseSet<Reference, Reference::Info> scratch;
-  bool isRecording;
-
-  explicit DependencyCollector(Mode mode)
-      : mode{mode}, requestReferences{}, scratch{}, isRecording{false} {};
-
-private:
-  void realizeOrRecord(const Reference &ref);
 
 public:
-  void replay(const swift::ActiveRequest &req);
+  explicit DependencyCollector(DependencyRecorder &parent) : parent(parent) {}
-  void record(const llvm::SetVector<swift::ActiveRequest> &stack,
-              llvm::function_ref<void(DependencyCollector &)> rec);
 
 public:
   /// Registers a named reference from the current dependency scope to a member
@@ -246,6 +217,50 @@ public:
   /// a name that is found by \c AnyObject lookup.
   void addDynamicLookupName(DeclBaseName name);
 
+public:
+  const DependencyRecorder &getRecorder() const { return parent; }
+  bool empty() const { return scratch.empty(); }
+};
+
+/// A \c DependencyCollector is an aggregator of named references discovered in a
+/// particular \c DependencyScope during the course of request evaluation.
+struct DependencyRecorder {
+  friend DependencyCollector;
+private:
+  /// A stack of dependency sources in the order they were evaluated.
+  llvm::SmallVector<evaluator::DependencySource, 8> dependencySources;
+
+public:
+  enum class Mode {
+    // Enables the current "status quo" behavior of the dependency collector.
+    //
+    // By default, the dependency collector moves to register dependencies in
+    // the referenced name trackers at the top of the active dependency stack.
+    StatusQuo,
+    // Enables an experimental mode to only register private dependencies.
+    //
+    // This mode restricts the dependency collector to ignore changes of
+    // scope. This has practical effect of charging all unqualified lookups to
+    // the primary file being acted upon instead of to the destination file.
+    ExperimentalPrivateDependencies,
+  };
+  Mode mode;
+  llvm::DenseMap<AnyRequest, llvm::DenseSet<DependencyCollector::Reference,
+                                            DependencyCollector::Reference::Info>>
+      requestReferences;
+  bool isRecording;
+
+  explicit DependencyRecorder(Mode mode)
+      : mode{mode}, requestReferences{}, isRecording{false} {};
+
+private:
+  void realize(const DependencyCollector::Reference &ref);
+
+public:
+  void replay(const swift::ActiveRequest &req);
+  void record(const llvm::SetVector<swift::ActiveRequest> &stack,
+              llvm::function_ref<void(DependencyCollector &)> rec);
+
 public:
   /// Returns the scope of the current active scope.
   ///
@@ -275,14 +290,14 @@ public:
   /// dependency source stack. It is specialized to be zero-cost for
   /// requests that are not dependency sources.
   template <typename Request, typename = detail::void_t<>> struct StackRAII {
-    StackRAII(DependencyCollector &DC, const Request &Req) {}
+    StackRAII(DependencyRecorder &DR, const Request &Req) {}
   };
 
   template <typename Request>
   struct StackRAII<Request,
                    typename std::enable_if<Request::isDependencySource>::type> {
-    NullablePtr<DependencyCollector> Coll;
+    NullablePtr<DependencyRecorder> Coll;
-    StackRAII(DependencyCollector &coll, const Request &Req) {
+    StackRAII(DependencyRecorder &coll, const Request &Req) {
       auto Source = Req.readDependencySource(coll);
       // If there is no source to introduce, bail. This can occur if
       // a request originates in the context of a module.

include/swift/AST/IRGenRequests.h

@@ -200,7 +200,7 @@ public:
 public:
   // Incremental dependencies.
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &) const;
+  readDependencySource(const evaluator::DependencyRecorder &) const;
 };
 
 class IRGenWholeModuleRequest

include/swift/AST/NameLookupRequests.h

@@ -189,7 +189,7 @@ public:
 public:
   // Incremental dependencies
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &e) const;
+  readDependencySource(const evaluator::DependencyRecorder &e) const;
   void writeDependencySink(evaluator::DependencyCollector &tracker,
                            ArrayRef<ProtocolDecl *> result) const;
 };
@@ -330,7 +330,7 @@ public:
 public:
   // Incremental dependencies.
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &) const;
+  readDependencySource(const evaluator::DependencyRecorder &) const;
 };
 
 class GenericParamListRequest :
@@ -434,7 +434,7 @@ private:
 public:
   // Incremental dependencies
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &) const;
+  readDependencySource(const evaluator::DependencyRecorder &) const;
   void writeDependencySink(evaluator::DependencyCollector &tracker,
                            LookupResult res) const;
 };
@@ -506,7 +506,7 @@ private:
 public:
   // Incremental dependencies
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &) const;
+  readDependencySource(const evaluator::DependencyRecorder &) const;
   void writeDependencySink(evaluator::DependencyCollector &tracker,
                            QualifiedLookupResult lookupResult) const;
 };
@@ -533,7 +533,7 @@ private:
 public:
   // Incremental dependencies.
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &) const;
+  readDependencySource(const evaluator::DependencyRecorder &) const;
 };
 
 /// The input type for a direct lookup request.

include/swift/AST/ParseRequests.h

@@ -103,7 +103,7 @@ public:
 
 public:
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &) const;
+  readDependencySource(const evaluator::DependencyRecorder &) const;
 };
 
 void simple_display(llvm::raw_ostream &out,
@@ -125,7 +125,7 @@ private:
 
 public:
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &) const;
+  readDependencySource(const evaluator::DependencyRecorder &) const;
 };
 
 /// The zone number for the parser.

include/swift/AST/SILGenRequests.h

@@ -104,7 +104,7 @@ private:
 public:
   // Incremental dependencies.
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &) const;
+  readDependencySource(const evaluator::DependencyRecorder &) const;
 };
 
 /// Parses a .sil file into a SILModule.

include/swift/AST/SimpleRequest.h

@@ -232,7 +232,7 @@ SourceLoc extractNearestSourceLoc(const std::tuple<First, Rest...> &value) {
 /// the 3 caching kinds defined above.
 /// \code
 ///   evaluator::DependencySource
-///   readDependencySource(const evaluator::DependencyCollector &) const;
+///   readDependencySource(const evaluator::DependencyRecorder &) const;
 /// \endcode
 ///
 /// Requests that define dependency sinks should instead override

include/swift/AST/TypeCheckRequests.h

@@ -123,7 +123,7 @@ public:
 public:
   // Incremental dependencies
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &e) const;
+  readDependencySource(const evaluator::DependencyRecorder &e) const;
   void writeDependencySink(evaluator::DependencyCollector &tracker,
                            Type t) const;
 };
@@ -893,7 +893,7 @@ public:
 public:
   // Incremental dependencies.
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &) const;
+  readDependencySource(const evaluator::DependencyRecorder &) const;
 };
 
 /// Request to obtain a list of stored properties in a nominal type.
@@ -2034,7 +2034,7 @@ public:
 public:
   // Incremental dependencies.
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &) const;
+  readDependencySource(const evaluator::DependencyRecorder &) const;
 };
 
 /// Computes whether the specified type or a super-class/super-protocol has the
@@ -2277,7 +2277,7 @@ private:
 public:
   // Incremental dependencies
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &eval) const;
+  readDependencySource(const evaluator::DependencyRecorder &eval) const;
   void writeDependencySink(evaluator::DependencyCollector &tracker,
                            ProtocolConformanceLookupResult r) const;
 };
@@ -2305,7 +2305,7 @@ public:
 
 public:
   evaluator::DependencySource
-  readDependencySource(const evaluator::DependencyCollector &eval) const;
+  readDependencySource(const evaluator::DependencyRecorder &eval) const;
   void writeDependencySink(evaluator::DependencyCollector &tracker,
                            evaluator::SideEffect) const;
 };

lib/AST/Evaluator.cpp

@@ -61,12 +61,13 @@ void Evaluator::registerRequestFunctions(
   requestFunctionsByZone.push_back({zoneID, functions});
 }
 
-static evaluator::DependencyCollector::Mode
+static evaluator::DependencyRecorder::Mode
 computeDependencyModeFromFlags(bool enableExperimentalPrivateDeps) {
-  using Mode = evaluator::DependencyCollector::Mode;
+  using Mode = evaluator::DependencyRecorder::Mode;
   if (enableExperimentalPrivateDeps) {
     return Mode::ExperimentalPrivateDependencies;
   }
+
   return Mode::StatusQuo;
 }
 
@@ -75,8 +76,7 @@ Evaluator::Evaluator(DiagnosticEngine &diags, bool debugDumpCycles,
                      bool enableExperimentalPrivateDeps)
     : diags(diags), debugDumpCycles(debugDumpCycles),
       buildDependencyGraph(buildDependencyGraph),
-      collector{computeDependencyModeFromFlags(enableExperimentalPrivateDeps)} {
+      recorder{computeDependencyModeFromFlags(enableExperimentalPrivateDeps)} {}
-}
 
 void Evaluator::emitRequestEvaluatorGraphViz(llvm::StringRef graphVizPath) {
   std::error_code error;
@@ -379,32 +379,27 @@ void Evaluator::dumpDependenciesGraphviz() const {
   printDependenciesGraphviz(llvm::dbgs());
 }
 
-void evaluator::DependencyCollector::realizeOrRecord(const Reference &ref) {
+void evaluator::DependencyRecorder::realize(
-  if (isRecording) {
+    const DependencyCollector::Reference &ref) {
-    scratch.insert(std::move(ref));
-    return;
-  }
-
   auto *tracker = getActiveDependencyTracker();
-  if (!tracker) {
+  assert(tracker && "cannot realize dependency without name tracker!");
-    return;
-  }
 
+  using Kind = evaluator::DependencyCollector::Reference::Kind;
   switch (ref.kind) {
-  case Reference::Kind::Empty:
+  case Kind::Empty:
-  case Reference::Kind::Tombstone:
+  case Kind::Tombstone:
     llvm_unreachable("cannot record empty dependency");
-  case Reference::Kind::UsedMember:
+  case Kind::UsedMember:
     tracker->addUsedMember({ref.subject, ref.name}, isActiveSourceCascading());
     break;
-  case Reference::Kind::PotentialMember:
+  case Kind::PotentialMember:
     tracker->addUsedMember({ref.subject, Identifier()},
                            isActiveSourceCascading());
     break;
-  case Reference::Kind::TopLevel:
+  case Kind::TopLevel:
     tracker->addTopLevelName(ref.name, isActiveSourceCascading());
     break;
-  case Reference::Kind::Dynamic:
+  case Kind::Dynamic:
     tracker->addDynamicLookupName(ref.name, isActiveSourceCascading());
     break;
   }
@@ -412,33 +407,55 @@ void evaluator::DependencyCollector::realizeOrRecord(const Reference &ref) {
 
 void evaluator::DependencyCollector::addUsedMember(NominalTypeDecl *subject,
                                                    DeclBaseName name) {
-  return realizeOrRecord(Reference::usedMember(subject, name));
+  if (parent.mode ==
+      DependencyRecorder::Mode::ExperimentalPrivateDependencies) {
+    scratch.insert(Reference::usedMember(subject, name));
+  }
+  return parent.realize(Reference::usedMember(subject, name));
 }
 
 void evaluator::DependencyCollector::addPotentialMember(
     NominalTypeDecl *subject) {
-  return realizeOrRecord(Reference::potentialMember(subject));
+  if (parent.mode ==
+      DependencyRecorder::Mode::ExperimentalPrivateDependencies) {
+    scratch.insert(Reference::potentialMember(subject));
+  }
+  return parent.realize(Reference::potentialMember(subject));
 }
 
 void evaluator::DependencyCollector::addTopLevelName(DeclBaseName name) {
-  return realizeOrRecord(Reference::topLevel(name));
+  if (parent.mode ==
+      DependencyRecorder::Mode::ExperimentalPrivateDependencies) {
+    scratch.insert(Reference::topLevel(name));
+  }
+  return parent.realize(Reference::topLevel(name));
 }
 
 void evaluator::DependencyCollector::addDynamicLookupName(DeclBaseName name) {
-  return realizeOrRecord(Reference::dynamic(name));
+  if (parent.mode ==
+      DependencyRecorder::Mode::ExperimentalPrivateDependencies) {
+    scratch.insert(Reference::dynamic(name));
+  }
+  return parent.realize(Reference::dynamic(name));
 }
 
-void evaluator::DependencyCollector::record(
+void evaluator::DependencyRecorder::record(
     const llvm::SetVector<swift::ActiveRequest> &stack,
     llvm::function_ref<void(DependencyCollector &)> rec) {
   assert(!isRecording && "Probably not a good idea to allow nested recording");
-  if (mode == Mode::StatusQuo) {
+  if (!getActiveDependencyTracker()) {
-    return rec(*this);
+    return;
   }
 
   llvm::SaveAndRestore<bool> restore(isRecording, true);
-  scratch = {};
+
-  rec(*this);
+  DependencyCollector collector{*this};
+  rec(collector);
+  if (collector.empty()) {
+    return;
+  }
+
+  assert(mode != Mode::StatusQuo);
   for (const auto &request : stack) {
     if (!request.isCached()) {
       continue;
@@ -446,26 +463,31 @@ void evaluator::DependencyCollector::record(
 
     auto entry = requestReferences.find_as(request);
     if (entry == requestReferences.end()) {
-      requestReferences.insert({AnyRequest(request), scratch});
+      requestReferences.insert({AnyRequest(request), collector.scratch});
       continue;
     }
 
-    entry->second.insert(scratch.begin(), scratch.end());
+    entry->second.insert(collector.scratch.begin(), collector.scratch.end());
   }
 }
 
-void evaluator::DependencyCollector::replay(const swift::ActiveRequest &req) {
+void evaluator::DependencyRecorder::replay(const swift::ActiveRequest &req) {
-  if (mode == Mode::StatusQuo) {
+  assert(!isRecording && "Probably not a good idea to allow nested recording");
+
+  if (mode == Mode::StatusQuo || !getActiveDependencyTracker()) {
+    return;
+  }
+
+  if (!req.isCached()) {
     return;
   }
 
-  assert(!isRecording && "Probably not a good idea to allow nested recording");
   auto entry = requestReferences.find_as(req);
   if (entry == requestReferences.end()) {
     return;
   }
 
   for (const auto &ref : entry->second) {
-    realizeOrRecord(ref);
+    realize(ref);
   }
 }

lib/AST/NameLookupRequests.cpp

@@ -89,7 +89,7 @@ void InheritedProtocolsRequest::cacheResult(ArrayRef<ProtocolDecl *> PDs) const
 }
 
 evaluator::DependencySource InheritedProtocolsRequest::readDependencySource(
-    const evaluator::DependencyCollector &e) const {
+    const evaluator::DependencyRecorder &e) const {
   auto *PD = std::get<0>(getStorage());
   // Ignore context changes for protocols outside our module. This
   // prevents transitive cascading edges when e.g. our private
@@ -184,7 +184,7 @@ void ExtendedNominalRequest::writeDependencySink(
   auto *SF = std::get<0>(getStorage())->getParentSourceFile();
   if (!SF)
     return;
-  if (SF != tracker.getActiveDependencySourceOrNull())
+  if (SF != tracker.getRecorder().getActiveDependencySourceOrNull())
     return;
   tracker.addPotentialMember(value);
 }
@@ -208,7 +208,7 @@ void GetDestructorRequest::cacheResult(DestructorDecl *value) const {
 }
 
 evaluator::DependencySource GetDestructorRequest::readDependencySource(
-    const evaluator::DependencyCollector &eval) const {
+    const evaluator::DependencyRecorder &eval) const {
   // Looking up the deinitializer currently always occurs in a private
   // scope because it is impossible to reference 'deinit' in user code, and a
   // valid 'deinit' declaration cannot occur outside of the
@@ -338,7 +338,7 @@ swift::extractNearestSourceLoc(const LookupConformanceDescriptor &desc) {
 //----------------------------------------------------------------------------//
 
 evaluator::DependencySource ModuleQualifiedLookupRequest::readDependencySource(
-    const evaluator::DependencyCollector &eval) const {
+    const evaluator::DependencyRecorder &eval) const {
   auto *DC = std::get<0>(getStorage());
   auto options = std::get<3>(getStorage());
 
@@ -385,7 +385,7 @@ void LookupConformanceInModuleRequest::writeDependencySink(
   if (!Adoptee)
     return;
 
-  auto *source = reqTracker.getActiveDependencySourceOrNull();
+  auto *source = reqTracker.getRecorder().getActiveDependencySourceOrNull();
   if (!source)
     return;
 
@@ -402,7 +402,7 @@ void LookupConformanceInModuleRequest::writeDependencySink(
 //----------------------------------------------------------------------------//
 
 evaluator::DependencySource UnqualifiedLookupRequest::readDependencySource(
-    const evaluator::DependencyCollector &) const {
+    const evaluator::DependencyRecorder &) const {
   auto &desc = std::get<0>(getStorage());
   // FIXME(Evaluator Incremental Dependencies): This maintains compatibility
   // with the existing scheme, but the existing scheme is totally ad-hoc. We
@@ -426,7 +426,7 @@ void UnqualifiedLookupRequest::writeDependencySink(
 //----------------------------------------------------------------------------//
 
 evaluator::DependencySource QualifiedLookupRequest::readDependencySource(
-    const evaluator::DependencyCollector &) const {
+    const evaluator::DependencyRecorder &) const {
   auto *dc = std::get<0>(getStorage());
   auto opts = std::get<3>(getStorage());
   // FIXME(Evaluator Incremental Dependencies): This is an artifact of the

lib/AST/TypeCheckRequests.cpp

@@ -158,7 +158,7 @@ void SuperclassTypeRequest::cacheResult(Type value) const {
 }
 
 evaluator::DependencySource SuperclassTypeRequest::readDependencySource(
-    const evaluator::DependencyCollector &e) const {
+    const evaluator::DependencyRecorder &e) const {
   const auto access = std::get<0>(getStorage())->getFormalAccess();
   return {
     e.getActiveDependencySourceOrNull(),
@@ -1349,7 +1349,7 @@ void CheckRedeclarationRequest::cacheResult(evaluator::SideEffect) const {
 }
 
 evaluator::DependencySource CheckRedeclarationRequest::readDependencySource(
-    const evaluator::DependencyCollector &eval) const {
+    const evaluator::DependencyRecorder &eval) const {
   auto *current = std::get<0>(getStorage());
   auto *currentDC = current->getDeclContext();
   return {
@@ -1384,7 +1384,7 @@ void CheckRedeclarationRequest::writeDependencySink(
 
 evaluator::DependencySource
 LookupAllConformancesInContextRequest::readDependencySource(
-    const evaluator::DependencyCollector &collector) const {
+    const evaluator::DependencyRecorder &collector) const {
   const auto *nominal = std::get<0>(getStorage())
                             ->getAsGenericContext()
                             ->getSelfNominalTypeDecl();
@@ -1427,7 +1427,7 @@ void ResolveTypeEraserTypeRequest::cacheResult(Type value) const {
 //----------------------------------------------------------------------------//
 
 evaluator::DependencySource TypeCheckSourceFileRequest::readDependencySource(
-    const evaluator::DependencyCollector &e) const {
+    const evaluator::DependencyRecorder &e) const {
   return {std::get<0>(getStorage()), evaluator::DependencyScope::Cascading};
 }
 
@@ -1460,7 +1460,7 @@ void TypeCheckSourceFileRequest::cacheResult(evaluator::SideEffect) const {
 
 evaluator::DependencySource
 TypeCheckFunctionBodyUntilRequest::readDependencySource(
-    const evaluator::DependencyCollector &e) const {
+    const evaluator::DependencyRecorder &e) const {
   // We're going under a function body scope, unconditionally flip the scope
   // to private.
   return {

lib/IRGen/IRGenRequests.cpp

@@ -53,7 +53,7 @@ SourceLoc swift::extractNearestSourceLoc(const IRGenDescriptor &desc) {
 }
 
 evaluator::DependencySource IRGenSourceFileRequest::readDependencySource(
-    const evaluator::DependencyCollector &e) const {
+    const evaluator::DependencyRecorder &e) const {
   auto &desc = std::get<0>(getStorage());
   return {
     desc.Ctx.dyn_cast<SourceFile *>(),

lib/Parse/ParseRequests.cpp

@@ -168,7 +168,7 @@ ArrayRef<Decl *> ParseSourceFileRequest::evaluate(Evaluator &evaluator,
 }
 
 evaluator::DependencySource ParseSourceFileRequest::readDependencySource(
-    const evaluator::DependencyCollector &e) const {
+    const evaluator::DependencyRecorder &e) const {
   return {std::get<0>(getStorage()), evaluator::DependencyScope::Cascading};
 }
 
@@ -196,7 +196,7 @@ void swift::simple_display(llvm::raw_ostream &out,
 
 evaluator::DependencySource
 CodeCompletionSecondPassRequest::readDependencySource(
-    const evaluator::DependencyCollector &e) const {
+    const evaluator::DependencyRecorder &e) const {
   return {std::get<0>(getStorage()), e.getActiveSourceScope()};
 }
 

lib/SILGen/SILGenRequests.cpp

@@ -47,7 +47,7 @@ SourceLoc swift::extractNearestSourceLoc(const SILGenDescriptor &desc) {
 }
 
 evaluator::DependencySource SILGenerationRequest::readDependencySource(
-    const evaluator::DependencyCollector &e) const {
+    const evaluator::DependencyRecorder &e) const {
   auto &desc = std::get<0>(getStorage());
 
   // We don't track dependencies in whole-module mode.