[BridgingHeader] Auto bridging header chaining

include/swift-c/DependencyScan/DependencyScan.h

@@ -25,7 +25,7 @@
 /// SWIFTSCAN_VERSION_MINOR should increase when there are API additions.
 /// SWIFTSCAN_VERSION_MAJOR is intended for "major" source/ABI breaking changes.
 #define SWIFTSCAN_VERSION_MAJOR 2
-#define SWIFTSCAN_VERSION_MINOR 0
+#define SWIFTSCAN_VERSION_MINOR 1
 
 SWIFTSCAN_BEGIN_DECLS
 
@@ -222,6 +222,14 @@ SWIFTSCAN_PUBLIC swiftscan_string_ref_t
 swiftscan_swift_textual_detail_get_user_module_version(
     swiftscan_module_details_t details);
 
+SWIFTSCAN_PUBLIC swiftscan_string_ref_t
+swiftscan_swift_textual_detail_get_chained_bridging_header_path(
+    swiftscan_module_details_t details);
+
+SWIFTSCAN_PUBLIC swiftscan_string_ref_t
+swiftscan_swift_textual_detail_get_chained_bridging_header_content(
+    swiftscan_module_details_t details);
+
 //=== Swift Binary Module Details query APIs ------------------------------===//
 
 SWIFTSCAN_PUBLIC swiftscan_string_ref_t

include/swift/AST/ModuleDependencies.h

@@ -30,11 +30,13 @@
 #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"
@@ -338,6 +340,12 @@ class SwiftSourceModuleDependenciesStorage
   /// The Swift frontend invocation arguments to build bridging header.
   std::vector<std::string> bridgingHeaderBuildCommandLine;
 
+  /// The chained bridging header path if used.
+  std::string chainedBridgingHeaderPath;
+
+  /// The chained bridging header source buffer if used.
+  std::string chainedBridgingHeaderContent;
+
   SwiftSourceModuleDependenciesStorage(
       StringRef RootID, ArrayRef<StringRef> buildCommandLine,
       ArrayRef<ScannerImportStatementInfo> moduleImports,
@@ -354,6 +362,7 @@ class SwiftSourceModuleDependenciesStorage
     return new SwiftSourceModuleDependenciesStorage(*this);
   }
 
+
   static bool classof(const ModuleDependencyInfoStorageBase *base) {
     return base->dependencyKind == ModuleDependencyKind::SwiftSource;
   }
@@ -370,6 +379,11 @@ class SwiftSourceModuleDependenciesStorage
   void addTestableImport(ImportPath::Module module) {
     testableImports.insert(module.front().Item.str());
   }
+
+  void setChainedBridgingHeaderBuffer(StringRef path, StringRef buffer) {
+    chainedBridgingHeaderPath = path.str();
+    chainedBridgingHeaderContent = buffer.str();
+  }
 };
 
 /// Describes the dependencies of a pre-built Swift module (with no
@@ -769,11 +783,11 @@ class ModuleDependencyInfo {
   setLinkLibraries(const ArrayRef<LinkLibrary> linkLibraries) {
     storage->linkLibraries.assign(linkLibraries.begin(), linkLibraries.end());
   }
-  
+
   const ArrayRef<std::string> getAuxiliaryFiles() const {
     return storage->auxiliaryFiles;
   }
-  
+
   void
   setAuxiliaryFiles(const ArrayRef<std::string> auxiliaryFiles) {
     storage->auxiliaryFiles.assign(auxiliaryFiles.begin(), auxiliaryFiles.end());
@@ -961,11 +975,14 @@ class ModuleDependencyInfo {
   void addSourceFile(StringRef sourceFile);
 
   /// Add source files that the header input depends on.
-  void addHeaderSourceFile(StringRef bridgingSourceFile);
+  void setHeaderSourceFiles(const std::vector<std::string> &sourceFiles);
 
   /// Add bridging header include tree.
   void addBridgingHeaderIncludeTree(StringRef ID);
 
+  /// Set the chained bridging header buffer.
+  void setChainedBridgingHeaderBuffer(StringRef path, StringRef buffer);
+
   /// Collect a map from a secondary module name to a list of cross-import
   /// overlays, when this current module serves as the primary module.
   llvm::StringMap<llvm::SmallSetVector<Identifier, 4>>
@@ -1025,8 +1042,9 @@ class SwiftDependencyScanningService {
   /// If use clang include tree.
   bool UseClangIncludeTree = false;
 
-  /// CAS ObjectStore Instance.
+  /// CAS Instance.
   std::shared_ptr<llvm::cas::ObjectStore> CAS;
+  std::shared_ptr<llvm::cas::ActionCache> ActionCache;
 
   /// File prefix mapper.
   std::unique_ptr<llvm::PrefixMapper> Mapper;
@@ -1182,11 +1200,11 @@ class ModuleDependenciesCache {
   /// Query all dependencies
   ModuleDependencyIDSetVector
   getAllDependencies(const ModuleDependencyID &moduleID) const;
-  
+
   /// Query all Clang module dependencies.
   ModuleDependencyIDSetVector
   getClangDependencies(const ModuleDependencyID &moduleID) const;
-  
+
   /// Query all directly-imported Swift dependencies
   llvm::ArrayRef<ModuleDependencyID>
   getImportedSwiftDependencies(const ModuleDependencyID &moduleID) const;

include/swift/AST/SearchPathOptions.h

@@ -577,6 +577,9 @@ class SearchPathOptions {
   /// "in-package", must not require package-only module dependencies.
   bool ResolveInPackageModuleDependencies = false;
 
+  /// Enable auto bridging header chaining.
+  bool BridgingHeaderChaining = false;
+
   /// Return all module search paths that (non-recursively) contain a file whose
   /// name is in \p Filenames.
   SmallVector<const ModuleSearchPath *, 4>

include/swift/Basic/LangOptions.h

@@ -201,7 +201,7 @@ namespace swift {
     /// Maximum number of typo corrections we are allowed to perform.
     /// This is disabled by default until we can get typo-correction working within acceptable performance bounds.
     unsigned TypoCorrectionLimit = 0;
-    
+
     /// Should access control be respected?
     bool EnableAccessControl = true;
 
@@ -260,7 +260,7 @@ namespace swift {
 
     /// Emit a remark when indexing a system module.
     bool EnableIndexingSystemModuleRemarks = false;
-    
+
     /// Emit a remark on early exit in explicit interface build
     bool EnableSkipExplicitInterfaceModuleBuildRemarks = false;
 
@@ -684,7 +684,7 @@ namespace swift {
     void clearAllPlatformConditionValues() {
       PlatformConditionValues.clear();
     }
-    
+
     /// Returns the value for the given platform condition or an empty string.
     StringRef getPlatformConditionValue(PlatformConditionKind Kind) const;
 
@@ -864,7 +864,7 @@ namespace swift {
     /// 4.2 GHz Intel Core i7.
     /// (It's arbitrary, but will keep the compiler from taking too much time.)
     unsigned SwitchCheckingInvocationThreshold = 200000;
-    
+
     /// If true, the time it takes to type-check each function will be dumped
     /// to llvm::errs().
     bool DebugTimeFunctionBodies = false;
@@ -908,7 +908,7 @@ namespace swift {
 
     /// Enable experimental operator designated types feature.
     bool EnableOperatorDesignatedTypes = false;
-    
+
     /// Disable constraint system performance hacks.
     bool DisableConstraintSolverPerformanceHacks = false;
 
@@ -956,6 +956,9 @@ namespace swift {
     /// The bridging header or PCH that will be imported.
     std::string BridgingHeader;
 
+    /// The bridging header PCH file.
+    std::string BridgingHeaderPCH;
+
     /// When automatically generating a precompiled header from the bridging
     /// header, place it in this directory.
     std::string PrecompiledHeaderOutputDir;
@@ -1077,6 +1080,9 @@ namespace swift {
     /// compilation source targets.
     std::vector<std::string>
     getReducedExtraArgsForSwiftModuleDependency() const;
+
+    /// Get PCH input path. Return empty string if there is no PCH input.
+    std::string getPCHInputPath() const;
   };
 
 } // end namespace swift

include/swift/ClangImporter/ClangImporter.h

@@ -508,14 +508,17 @@ class ClangImporter final : public ClangModuleLoader {
   /// information will be augmented with information about the given
   /// textual header inputs.
   ///
+  /// \param headerPath the path to the header to be scanned.
+  ///
   /// \param clangScanningTool The clang dependency scanner.
   ///
   /// \param cache The module dependencies cache to update, with information
   /// about new Clang modules discovered along the way.
   ///
   /// \returns \c true if an error occurred, \c false otherwise
   bool getHeaderDependencies(
-      ModuleDependencyID moduleID,
+      ModuleDependencyID moduleID, std::optional<StringRef> headerPath,
+      std::optional<llvm::MemoryBufferRef> sourceBuffer,
       clang::tooling::dependencies::DependencyScanningTool &clangScanningTool,
       ModuleDependenciesCache &cache,
       ModuleDependencyIDSetVector &headerClangModuleDependencies,
@@ -677,6 +680,11 @@ class ClangImporter final : public ClangModuleLoader {
   const clang::TypedefType *getTypeDefForCXXCFOptionsDefinition(
       const clang::Decl *candidateDecl) override;
 
+  /// Create cache key for embedded bridging header.
+  static llvm::Expected<llvm::cas::ObjectRef>
+  createEmbeddedBridgingHeaderCacheKey(
+      llvm::cas::ObjectStore &CAS, llvm::cas::ObjectRef ChainedPCHIncludeTree);
+
   SourceLoc importSourceLocation(clang::SourceLocation loc) override;
 };
 

include/swift/DependencyScan/DependencyScanImpl.h

@@ -130,6 +130,13 @@ typedef struct {
 
   /// User module version
   swiftscan_string_ref_t user_module_version;
+
+  /// Chained bridging header path.
+  swiftscan_string_ref_t chained_bridging_header_path;
+
+  /// Chained bridging header content.
+  swiftscan_string_ref_t chained_bridging_header_content;
+
 } swiftscan_swift_textual_details_t;
 
 /// Swift modules with only a binary module file.

include/swift/DependencyScan/ModuleDependencyScanner.h

@@ -16,6 +16,7 @@
 #include "swift/AST/ModuleDependencies.h"
 #include "swift/Frontend/ModuleInterfaceLoader.h"
 #include "swift/Serialization/SerializedModuleLoader.h"
+#include "llvm/CAS/CASReference.h"
 #include "llvm/Support/ThreadPool.h"
 
 namespace swift {
@@ -48,6 +49,11 @@ class ModuleDependencyScanningWorker {
                                          llvm::PrefixMapper *prefixMapper,
                                          bool isTestableImport = false);
 
+  /// Store cache entry for include tree.
+  llvm::Error
+  createCacheKeyForEmbeddedHeader(std::string embeddedHeaderIncludeTree,
+                                  std::string chainedHeaderIncludeTree);
+
   // Worker-specific instance of CompilerInvocation
   std::unique_ptr<CompilerInvocation> workerCompilerInvocation;
   // Worker-specific instance of ASTContext
@@ -59,6 +65,9 @@ class ModuleDependencyScanningWorker {
   // Swift and Clang module loaders acting as scanners.
   std::unique_ptr<ModuleInterfaceLoader> swiftScannerModuleLoader;
   std::unique_ptr<ClangImporter> clangScannerModuleLoader;
+  // CAS instance.
+  std::shared_ptr<llvm::cas::ObjectStore> CAS;
+  std::shared_ptr<llvm::cas::ActionCache> ActionCache;
   // Restrict access to the parent scanner class.
   friend class ModuleDependencyScanner;
 };
@@ -116,10 +125,9 @@ class ModuleDependencyScanner {
   resolveAllClangModuleDependencies(ArrayRef<ModuleDependencyID> swiftModules,
                                     ModuleDependenciesCache &cache,
                                     ModuleDependencyIDSetVector &discoveredClangModules);
-  void
-  resolveHeaderDependencies(ArrayRef<ModuleDependencyID> swiftModules,
-                            ModuleDependenciesCache &cache,
-                            ModuleDependencyIDSetVector &discoveredHeaderDependencyClangModules);
+  void resolveHeaderDependencies(
+      ArrayRef<ModuleDependencyID> swiftModules, ModuleDependenciesCache &cache,
+      ModuleDependencyIDSetVector &discoveredHeaderDependencyClangModules);
   void
   resolveSwiftOverlayDependencies(ArrayRef<ModuleDependencyID> swiftModules,
                                   ModuleDependenciesCache &cache,
@@ -151,6 +159,12 @@ class ModuleDependencyScanner {
       ModuleDependenciesCache &cache,
       llvm::function_ref<void(ModuleDependencyID)> action);
 
+  /// Performance BridgingHeader Chaining.
+  llvm::Error
+  performBridgingHeaderChaining(const ModuleDependencyID &rootModuleID,
+                                ModuleDependenciesCache &cache,
+                                ModuleDependencyIDSetVector &allModules);
+
   /// Perform an operation utilizing one of the Scanning workers
   /// available to this scanner.
   template <typename Function, typename... Args>

include/swift/DependencyScan/SerializedModuleDependencyCacheFormat.h

@@ -233,7 +233,9 @@ using SwiftSourceModuleDetailsLayout =
                    IdentifierIDField,                // CASFileSystemRootID
                    IdentifierIDField,                // bridgingHeaderIncludeTree
                    FlagIDArrayIDField,               // buildCommandLine
-                   FlagIDArrayIDField                // bridgingHeaderBuildCommandLine
+                   FlagIDArrayIDField,               // bridgingHeaderBuildCommandLine
+                   IdentifierIDField,                // chainedBridgingHeaderPath
+                   IdentifierIDField                 // chainedBridgingHeaderContent
                    >;
 
 using SwiftBinaryModuleDetailsLayout =

include/swift/Frontend/CompileJobCacheKey.h

@@ -21,6 +21,7 @@
 #include "swift/AST/DiagnosticEngine.h"
 #include "swift/Basic/FileTypes.h"
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/CAS/CASReference.h"
 #include "llvm/CAS/ObjectStore.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/raw_ostream.h"
@@ -49,6 +50,7 @@ createCompileJobCacheKeyForOutput(llvm::cas::ObjectStore &CAS,
 llvm::Error printCompileJobCacheKey(llvm::cas::ObjectStore &CAS,
                                     llvm::cas::ObjectRef Key,
                                     llvm::raw_ostream &os);
+
 } // namespace swift
 
 #endif

include/swift/Frontend/FrontendOptions.h

@@ -54,6 +54,9 @@ class FrontendOptions {
   /// An Objective-C header to import and make implicitly visible.
   std::string ImplicitObjCHeaderPath;
 
+  /// An Objective-C pch to import and make implicitly visible.
+  std::string ImplicitObjCPCHPath;
+
   /// The map of aliases and real names of imported or referenced modules.
   llvm::StringMap<StringRef> ModuleAliasMap;
 
@@ -374,6 +377,12 @@ class FrontendOptions {
   /// Emit remarks indicating use of the serialized module dependency scanning cache.
   bool EmitDependencyScannerCacheRemarks = false;
 
+  /// The path at which the dependency scanner can write generated files.
+  std::string ScannerOutputDir;
+
+  /// If the scanner output is written directly to the disk for debugging.
+  bool WriteScannerOutput = false;
+
   /// Whether the dependency scanner invocation should resolve imports
   /// to filesystem modules in parallel.
   bool ParallelDependencyScan = true;