[Dependency Scanning] Have 'ModuleDependnecyScanner' hold a reference to a dependency cache, instead of passing it around

include/swift/DependencyScan/ModuleDependencyScanner.h

@@ -216,13 +216,14 @@ private:
 class ModuleDependencyScanner {
 public:
   ModuleDependencyScanner(SwiftDependencyScanningService &ScanningService,
+                          ModuleDependenciesCache &Cache,
                           const CompilerInvocation &ScanCompilerInvocation,
                           const SILOptions &SILOptions,
                           ASTContext &ScanASTContext,
                           DependencyTracker &DependencyTracker,
                           std::shared_ptr<llvm::cas::ObjectStore> CAS,
                           std::shared_ptr<llvm::cas::ActionCache> ActionCache,
-                          DiagnosticEngine &diags, bool ParallelScan);
+                          DiagnosticEngine &Diagnostics, bool ParallelScan);
 
   /// Identify the scanner invocation's main module's dependencies
   llvm::ErrorOr<ModuleDependencyInfo>
@@ -231,8 +232,7 @@ public:
   /// Resolve module dependencies of the given module, computing a full
   /// transitive closure dependency graph.
   std::vector<ModuleDependencyID>
-  performDependencyScan(ModuleDependencyID rootModuleID,
-                        ModuleDependenciesCache &cache);
+  performDependencyScan(ModuleDependencyID rootModuleID);
 
   /// How many filesystem lookups were performed by the scanner
   unsigned getNumLookups() { return NumLookups; }
@@ -275,47 +275,46 @@ private:
   /// that have one
   ModuleDependencyIDSetVector
   resolveImportedModuleDependencies(
-      const ModuleDependencyID &rootModuleID, ModuleDependenciesCache &cache);
+      const ModuleDependencyID &rootModuleID);
   void resolveSwiftModuleDependencies(
-      const ModuleDependencyID &rootModuleID, ModuleDependenciesCache &cache,
+      const ModuleDependencyID &rootModuleID,
       ModuleDependencyIDSetVector &discoveredSwiftModules);
   void resolveAllClangModuleDependencies(
-      ArrayRef<ModuleDependencyID> swiftModules, ModuleDependenciesCache &cache,
+      ArrayRef<ModuleDependencyID> swiftModules,
       ModuleDependencyIDSetVector &discoveredClangModules);
   void resolveHeaderDependencies(
-      ArrayRef<ModuleDependencyID> swiftModules, ModuleDependenciesCache &cache,
+      ArrayRef<ModuleDependencyID> swiftModules,
       ModuleDependencyIDSetVector &discoveredHeaderDependencyClangModules);
   void resolveSwiftOverlayDependencies(
-      ArrayRef<ModuleDependencyID> swiftModules, ModuleDependenciesCache &cache,
+      ArrayRef<ModuleDependencyID> swiftModules,
       ModuleDependencyIDSetVector &discoveredDependencies);
 
   /// Resolve all of a given module's imports to a Swift module, if one exists.
   void resolveSwiftImportsForModule(
-      const ModuleDependencyID &moduleID, ModuleDependenciesCache &cache,
+      const ModuleDependencyID &moduleID,
       ModuleDependencyIDSetVector &importedSwiftDependencies);
 
   /// If a module has a bridging header or other header inputs, execute a
   /// dependency scan on it and record the dependencies.
   void resolveHeaderDependenciesForModule(
-      const ModuleDependencyID &moduleID, ModuleDependenciesCache &cache,
+      const ModuleDependencyID &moduleID,
       ModuleDependencyIDSetVector &headerClangModuleDependencies);
 
   /// Resolve all module dependencies comprised of Swift overlays
   /// of this module's Clang module dependencies.
   void resolveSwiftOverlayDependenciesForModule(
-      const ModuleDependencyID &moduleID, ModuleDependenciesCache &cache,
+      const ModuleDependencyID &moduleID,
       ModuleDependencyIDSetVector &swiftOverlayDependencies);
 
   /// Identify all cross-import overlay module dependencies of the
   /// source module under scan and apply an action for each.
   void resolveCrossImportOverlayDependencies(
-      StringRef mainModuleName, ModuleDependenciesCache &cache,
+      StringRef mainModuleName,
       llvm::function_ref<void(ModuleDependencyID)> action);
 
   /// Perform Bridging Header Chaining.
   llvm::Error
   performBridgingHeaderChaining(const ModuleDependencyID &rootModuleID,
-                                ModuleDependenciesCache &cache,
                                 ModuleDependencyIDSetVector &allModules);
 
   /// Bridge Clang dependency scanner's dependency node
@@ -351,7 +350,6 @@ private:
   void performParallelClangModuleLookup(
       const ImportStatementInfoMap &unresolvedImportsMap,
       const ImportStatementInfoMap &unresolvedOptionalImportsMap,
-      ModuleDependenciesCache &cache,
       BatchClangModuleLookupResult &result);
 
   /// Given a result of a batch Clang module dependency lookup,
@@ -371,7 +369,6 @@ private:
       const ImportStatementInfoMap &unresolvedImportsMap,
       const ImportStatementInfoMap &unresolvedOptionalImportsMap,
       ArrayRef<ModuleDependencyID> swiftModuleDependents,
-      ModuleDependenciesCache &cache,
       ModuleDependencyIDSetVector &allDiscoveredClangModules,
       std::vector<std::pair<ModuleDependencyID, ScannerImportStatementInfo>>
           &failedToResolveImports,
@@ -381,7 +378,6 @@ private:
   /// Re-query some failed-to-resolve Clang imports from cache
   /// in chance they were brought in as transitive dependencies.
   void reQueryMissedModulesFromCache(
-      ModuleDependenciesCache &cache,
       const std::vector<
           std::pair<ModuleDependencyID, ScannerImportStatementInfo>>
           &failedToResolveImports,
@@ -395,8 +391,7 @@ private:
   /// the module, if one is found.
   std::optional<std::pair<ModuleDependencyID, std::string>>
   attemptToFindResolvingSerializedSearchPath(
-      const ScannerImportStatementInfo &moduleImport,
-      const ModuleDependenciesCache &cache);
+      const ScannerImportStatementInfo &moduleImport);
 
 private:
   const CompilerInvocation &ScanCompilerInvocation;
@@ -407,6 +402,9 @@ private:
   std::string ModuleOutputPath;
   /// The location of where the explicitly-built SDK modules will be output to
   std::string SDKModuleOutputPath;
+  
+  /// Reference to a module dependency cache
+  ModuleDependenciesCache &DependencyCache;
 
   /// The available pool of workers for filesystem module search
   unsigned NumThreads;