[Caching] Move per-query CAS state out of the SwiftDependencyScanningService

Move per-query state out of ScanningService. There is still a check to
make sure the CASOptions are matching between queries because of the
requirement on clang scanner. Otherwise, the scanning service should
contain no per-query information anymore.

Resolves: #82490

Author: cachemeifyoucan

include/swift/AST/ModuleDependencies.h

@@ -25,22 +25,13 @@
 #include "swift/Serialization/Validation.h"
 #include "clang/CAS/CASOptions.h"
 #include "clang/Tooling/DependencyScanning/DependencyScanningService.h"
-#include "clang/Tooling/DependencyScanning/DependencyScanningTool.h"
 #include "clang/Tooling/DependencyScanning/ModuleDepCollector.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/StringSet.h"
-#include "llvm/CAS/ActionCache.h"
-#include "llvm/CAS/CASProvidingFileSystem.h"
-#include "llvm/CAS/CASReference.h"
 #include "llvm/CAS/CachingOnDiskFileSystem.h"
-#include "llvm/CAS/ObjectStore.h"
-#include "llvm/Support/Error.h"
-#include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Mutex.h"
-#include "llvm/Support/PrefixMapper.h"
-#include "llvm/Support/VirtualFileSystem.h"
 #include <optional>
 #include <string>
 #include <unordered_map>
@@ -945,34 +936,6 @@ using ModuleDependenciesKindMap =
     std::unordered_map<ModuleDependencyKind, ModuleNameToDependencyMap,
                        ModuleDependencyKindHash>;
 
-// MARK: SwiftDependencyTracker
-/// Track swift dependency
-class SwiftDependencyTracker {
-public:
-  SwiftDependencyTracker(std::shared_ptr<llvm::cas::ObjectStore> CAS,
-                         llvm::PrefixMapper *Mapper,
-                         const CompilerInvocation &CI);
-
-  void startTracking(bool includeCommonDeps = true);
-  void trackFile(const Twine &path);
-  llvm::Expected<llvm::cas::ObjectProxy> createTreeFromDependencies();
-
-private:
-  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS;
-  std::shared_ptr<llvm::cas::ObjectStore> CAS;
-  llvm::PrefixMapper *Mapper;
-
-  struct FileEntry {
-    llvm::cas::ObjectRef FileRef;
-    size_t Size;
-
-    FileEntry(llvm::cas::ObjectRef FileRef, size_t Size)
-        : FileRef(FileRef), Size(Size) {}
-  };
-  llvm::StringMap<FileEntry> CommonFiles;
-  std::map<std::string, FileEntry> TrackedFiles;
-};
-
 // MARK: SwiftDependencyScanningService
 /// A carrier of state shared among possibly multiple invocations of the
 /// dependency scanner.
@@ -984,21 +947,6 @@ class SwiftDependencyScanningService {
   std::optional<clang::tooling::dependencies::DependencyScanningService>
       ClangScanningService;
 
-  /// CachingOnDiskFileSystem for dependency tracking.
-  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> CacheFS;
-
-  /// CAS Instance.
-  std::shared_ptr<llvm::cas::ObjectStore> CAS;
-  std::shared_ptr<llvm::cas::ActionCache> ActionCache;
-
-  /// File prefix mapper.
-  std::shared_ptr<llvm::PrefixMapper> Mapper;
-
-  /// The global file system cache.
-  std::optional<
-      clang::tooling::dependencies::DependencyScanningFilesystemSharedCache>
-      SharedFilesystemCache;
-
   /// Shared state mutual-exclusivity lock
   mutable llvm::sys::SmartMutex<true> ScanningServiceGlobalLock;
 
@@ -1010,52 +958,6 @@ class SwiftDependencyScanningService {
   operator=(const SwiftDependencyScanningService &) = delete;
   virtual ~SwiftDependencyScanningService() {}
 
-  /// Query the service's filesystem cache
-  clang::tooling::dependencies::DependencyScanningFilesystemSharedCache &getSharedCache() {
-    assert(SharedFilesystemCache && "Expected a shared cache");
-    return *SharedFilesystemCache;
-  }
-
-  /// Query the service's filesystem cache
-  clang::tooling::dependencies::DependencyScanningFilesystemSharedCache &
-  getSharedFilesystemCache() {
-    assert(SharedFilesystemCache && "Expected a shared cache");
-    return *SharedFilesystemCache;
-  }
-
-  llvm::vfs::FileSystem &getSharedCachingFS() const {
-    assert(CacheFS && "Expect a CASFileSystem");
-    return *CacheFS;
-  }
-
-  llvm::cas::ObjectStore &getCAS() const {
-    assert(CAS && "Expect CAS available");
-    return *CAS;
-  }
-
-  std::optional<SwiftDependencyTracker>
-  createSwiftDependencyTracker(const CompilerInvocation &CI) {
-    if (!CAS)
-      return std::nullopt;
-
-    return SwiftDependencyTracker(CAS, Mapper.get(), CI);
-  }
-
-  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>
-  getClangScanningFS(ASTContext &ctx) const;
-
-  bool hasPathMapping() const {
-    return Mapper && !Mapper->getMappings().empty();
-  }
-  llvm::PrefixMapper *getPrefixMapper() const { return Mapper.get(); }
-  std::string remapPath(StringRef Path) const {
-    if (!Mapper)
-      return Path.str();
-    return Mapper->mapToString(Path);
-  }
-
-  bool hasCAS() const { return (bool)CAS; }
-
   /// Setup caching service.
   bool setupCachingDependencyScanningService(CompilerInstance &Instance);
 

include/swift/AST/ModuleLoader.h

@@ -24,8 +24,6 @@
 #include "swift/Basic/LLVM.h"
 #include "swift/Basic/Located.h"
 #include "swift/Basic/SourceLoc.h"
-#include "clang/Basic/FileManager.h"
-#include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/ADT/TinyPtrVector.h"
@@ -38,11 +36,8 @@ class FileCollectorBase;
 class PrefixMapper;
 namespace vfs {
 class OutputBackend;
-}
-namespace cas {
-class CachingOnDiskFileSystem;
-}
-}
+} // namespace vfs
+} // namespace llvm
 
 namespace clang {
 class DependencyCollector;

include/swift/DependencyScan/ModuleDependencyScanner.h

@@ -1,5 +1,4 @@
-//===--- ModuleDependencyScanner.h - Import Swift modules --------*- C++
-//-*-===//
+//===--- ModuleDependencyScanner.h - Import Swift modules ------*- C++ -*-===//
 //
 // This source file is part of the Swift.org open source project
 //
@@ -16,6 +15,7 @@
 #include "swift/AST/ModuleDependencies.h"
 #include "swift/Frontend/ModuleInterfaceLoader.h"
 #include "swift/Serialization/ScanningLoaders.h"
+#include "clang/Tooling/DependencyScanning/DependencyScanningTool.h"
 #include "llvm/CAS/CASReference.h"
 #include "llvm/Support/ThreadPool.h"
 
@@ -33,7 +33,10 @@ class ModuleDependencyScanningWorker {
       SwiftDependencyScanningService &globalScanningService,
       const CompilerInvocation &ScanCompilerInvocation,
       const SILOptions &SILOptions, ASTContext &ScanASTContext,
-      DependencyTracker &DependencyTracker, DiagnosticEngine &diags);
+      DependencyTracker &DependencyTracker,
+      std::shared_ptr<llvm::cas::ObjectStore> CAS,
+      std::shared_ptr<llvm::cas::ActionCache> ActionCache,
+      llvm::PrefixMapper *mapper, DiagnosticEngine &diags);
 
 private:
   /// Retrieve the module dependencies for the Clang module with the given name.
@@ -97,7 +100,7 @@ class ModuleDependencyScanningWorker {
   std::shared_ptr<llvm::cas::ObjectStore> CAS;
   std::shared_ptr<llvm::cas::ActionCache> ActionCache;
   /// File prefix mapper.
-  std::shared_ptr<llvm::PrefixMapper> PrefixMapper;
+  llvm::PrefixMapper *PrefixMapper;
 
   // Base command line invocation for clang scanner queries (both module and header)
   std::vector<std::string> clangScanningBaseCommandLineArgs;
@@ -112,13 +115,43 @@ class ModuleDependencyScanningWorker {
   friend class ModuleDependencyScanner;
 };
 
+// MARK: SwiftDependencyTracker
+/// Track swift dependency
+class SwiftDependencyTracker {
+public:
+  SwiftDependencyTracker(std::shared_ptr<llvm::cas::ObjectStore> CAS,
+                         llvm::PrefixMapper *Mapper,
+                         const CompilerInvocation &CI);
+
+  void startTracking(bool includeCommonDeps = true);
+  void trackFile(const Twine &path);
+  llvm::Expected<llvm::cas::ObjectProxy> createTreeFromDependencies();
+
+private:
+  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS;
+  std::shared_ptr<llvm::cas::ObjectStore> CAS;
+  llvm::PrefixMapper *Mapper;
+
+  struct FileEntry {
+    llvm::cas::ObjectRef FileRef;
+    size_t Size;
+
+    FileEntry(llvm::cas::ObjectRef FileRef, size_t Size)
+        : FileRef(FileRef), Size(Size) {}
+  };
+  llvm::StringMap<FileEntry> CommonFiles;
+  std::map<std::string, FileEntry> TrackedFiles;
+};
+
 class ModuleDependencyScanner {
 public:
   ModuleDependencyScanner(SwiftDependencyScanningService &ScanningService,
                           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);
 
   /// Identify the scanner invocation's main module's dependencies
@@ -134,6 +167,37 @@ class ModuleDependencyScanner {
   /// How many filesystem lookups were performed by the scanner
   unsigned getNumLookups() { return NumLookups; }
 
+  /// CAS Dependency Tracker.
+  std::optional<SwiftDependencyTracker>
+  createSwiftDependencyTracker(const CompilerInvocation &CI) {
+    if (!CAS)
+      return std::nullopt;
+
+    return SwiftDependencyTracker(CAS, PrefixMapper.get(), CI);
+  }
+
+  /// PrefixMapper for scanner.
+  bool hasPathMapping() const {
+    return PrefixMapper && !PrefixMapper->getMappings().empty();
+  }
+  llvm::PrefixMapper *getPrefixMapper() const { return PrefixMapper.get(); }
+  std::string remapPath(StringRef Path) const {
+    if (!PrefixMapper)
+      return Path.str();
+    return PrefixMapper->mapToString(Path);
+  }
+
+  /// CAS options.
+  llvm::cas::ObjectStore &getCAS() const {
+    assert(CAS && "Expect CAS available");
+    return *CAS;
+  }
+
+  llvm::vfs::FileSystem &getSharedCachingFS() const {
+    assert(CacheFS && "Expect CacheFS available");
+    return *CacheFS;
+  }
+
 private:
   /// Main routine that computes imported module dependency transitive
   /// closure for the given module.
@@ -222,8 +286,13 @@ class ModuleDependencyScanner {
   unsigned NumThreads;
   std::list<std::unique_ptr<ModuleDependencyScanningWorker>> Workers;
   llvm::DefaultThreadPool ScanningThreadPool;
+  // CAS instance.
+  std::shared_ptr<llvm::cas::ObjectStore> CAS;
+  std::shared_ptr<llvm::cas::ActionCache> ActionCache;
   /// File prefix mapper.
-  std::shared_ptr<llvm::PrefixMapper> PrefixMapper;
+  std::unique_ptr<llvm::PrefixMapper> PrefixMapper;
+  /// CAS file system for loading file content.
+  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> CacheFS;
   /// Protect worker access.
   std::mutex WorkersLock;
   /// Count of filesystem queries performed

include/swift/DependencyScan/ScanDependencies.h

@@ -22,6 +22,9 @@
 
 namespace llvm {
 class StringSaver;
+namespace cas {
+class ObjectStore;
+} // namespace cas
 namespace vfs {
 class FileSystem;
 } // namespace vfs
@@ -77,18 +80,18 @@ namespace incremental {
 /// than the serialized dependency graph, it is considered invalidated and must
 /// be re-scanned.
 void validateInterModuleDependenciesCache(
-    const SwiftDependencyScanningService &service,
     const ModuleDependencyID &rootModuleID, ModuleDependenciesCache &cache,
+    std::shared_ptr<llvm::cas::ObjectStore> cas,
     const llvm::sys::TimePoint<> &cacheTimeStamp, llvm::vfs::FileSystem &fs,
     DiagnosticEngine &diags, bool emitRemarks = false);
 
 /// Perform a postorder DFS to locate modules whose build recipe is out-of-date
 /// with respect to their inputs. Upon encountering such a module, add it to the
 /// set of invalidated modules, along with the path from the root to this
 /// module.
-void outOfDateModuleScan(const SwiftDependencyScanningService &service,
-                         const ModuleDependencyID &sourceModuleID,
+void outOfDateModuleScan(const ModuleDependencyID &sourceModuleID,
                          const ModuleDependenciesCache &cache,
+                         std::shared_ptr<llvm::cas::ObjectStore> cas,
                          const llvm::sys::TimePoint<> &cacheTimeStamp,
                          llvm::vfs::FileSystem &fs, DiagnosticEngine &diags,
                          bool emitRemarks, ModuleDependencyIDSet &visited,
@@ -97,8 +100,8 @@ void outOfDateModuleScan(const SwiftDependencyScanningService &service,
 /// Validate whether all inputs of a given module dependency
 /// are older than the cache serialization time.
 bool verifyModuleDependencyUpToDate(
-    const SwiftDependencyScanningService &service,
     const ModuleDependencyID &moduleID, const ModuleDependenciesCache &cache,
+    std::shared_ptr<llvm::cas::ObjectStore> cas,
     const llvm::sys::TimePoint<> &cacheTimeStamp, llvm::vfs::FileSystem &fs,
     DiagnosticEngine &diags, bool emitRemarks);
 } // end namespace incremental