[6.0][Caching] SwiftDriver changes for caching support

Sources/SwiftDriver/Driver/Driver.swift

@@ -336,7 +336,14 @@ public struct Driver {
   let importedObjCHeader: VirtualPath.Handle?
 
   /// The path to the pch for the imported Objective-C header.
-  let bridgingPrecompiledHeader: VirtualPath.Handle?
+  lazy var bridgingPrecompiledHeader: VirtualPath.Handle? = {
+    let contextHash = try? explicitDependencyBuildPlanner?.getMainModuleContextHash()
+    return Self.computeBridgingPrecompiledHeader(&parsedOptions,
+                                                 compilerMode: compilerMode,
+                                                 importedObjCHeader: importedObjCHeader,
+                                                 outputFileMap: outputFileMap,
+                                                 contextHash: contextHash)
+  }()
 
   /// Path to the dependencies file.
   let dependenciesFilePath: VirtualPath.Handle?
@@ -801,10 +808,6 @@ public struct Driver {
       recordedInputModificationDates: recordedInputModificationDates)
 
     self.importedObjCHeader = try Self.computeImportedObjCHeader(&parsedOptions, compilerMode: compilerMode, diagnosticEngine: diagnosticEngine)
-    self.bridgingPrecompiledHeader = try Self.computeBridgingPrecompiledHeader(&parsedOptions,
-                                                                               compilerMode: compilerMode,
-                                                                               importedObjCHeader: importedObjCHeader,
-                                                                               outputFileMap: outputFileMap)
 
     self.supportedFrontendFlags =
       try Self.computeSupportedCompilerArgs(of: self.toolchain,
@@ -829,7 +832,7 @@ public struct Driver {
         diagnosticsEngine.emit(.warning("-cache-compile-job cannot be used without explicit module build, turn off caching"),
                                location: nil)
         self.enableCaching = false
-      } else if importedObjCHeader != nil && bridgingPrecompiledHeader == nil {
+      } else if importedObjCHeader != nil, !parsedOptions.hasFlag(positive: .enableBridgingPch, negative: .disableBridgingPch, default: true) {
         diagnosticsEngine.emit(.warning("-cache-compile-job cannot be used with -disable-bridging-pch, turn off caching"),
                                location: nil)
         self.enableCaching = false
@@ -1779,7 +1782,7 @@ extension Driver {
   /// The swift-driver doesn't have actions, so the logic here takes the jobs and tries
   /// to mimic the actions that would be created by the C++ driver and
   /// prints them in *hopefully* the same order.
-  private func printActions(_ jobs: [Job]) {
+  private mutating func printActions(_ jobs: [Job]) {
     defer {
       stdoutStream.flush()
     }
@@ -2872,23 +2875,29 @@ extension Driver {
   static func computeBridgingPrecompiledHeader(_ parsedOptions: inout ParsedOptions,
                                                compilerMode: CompilerMode,
                                                importedObjCHeader: VirtualPath.Handle?,
-                                               outputFileMap: OutputFileMap?) throws -> VirtualPath.Handle? {
+                                               outputFileMap: OutputFileMap?,
+                                               contextHash: String?) -> VirtualPath.Handle? {
     guard compilerMode.supportsBridgingPCH,
       let input = importedObjCHeader,
       parsedOptions.hasFlag(positive: .enableBridgingPch, negative: .disableBridgingPch, default: true) else {
         return nil
     }
 
-    if let outputPath = try outputFileMap?.existingOutput(inputFile: input, outputType: .pch) {
+    if let outputPath = try? outputFileMap?.existingOutput(inputFile: input, outputType: .pch) {
       return outputPath
     }
 
-    let inputFile = VirtualPath.lookup(input)
-    let pchFileName = inputFile.basenameWithoutExt.appendingFileTypeExtension(.pch)
+    let pchFile : String
+    let baseName = VirtualPath.lookup(input).basenameWithoutExt
+    if let hash = contextHash {
+      pchFile = baseName + "-" + hash + ".pch"
+    } else {
+      pchFile = baseName.appendingFileTypeExtension(.pch)
+    }
     if let outputDirectory = parsedOptions.getLastArgument(.pchOutputDir)?.asSingle {
-      return try VirtualPath(path: outputDirectory).appending(component: pchFileName).intern()
+      return try? VirtualPath(path: outputDirectory).appending(component: pchFile).intern()
     } else {
-      return try VirtualPath.createUniqueTemporaryFile(RelativePath(validating: pchFileName)).intern()
+      return try? VirtualPath.temporary(RelativePath(validating: pchFile)).intern()
     }
   }
 }

Sources/SwiftDriver/ExplicitModuleBuilds/ExplicitDependencyBuildPlanner.swift

@@ -425,6 +425,13 @@ public typealias ExternalTargetModuleDetailsMap = [ModuleDependencyId: ExternalT
     commandLine.append(contentsOf: mainModuleDependenciesArgs.commandLine)
   }
 
+  /// Get the context hash for the main module.
+  public func getMainModuleContextHash() throws -> String? {
+    let mainModuleId: ModuleDependencyId = .swift(dependencyGraph.mainModuleName)
+    let mainModuleDetails = try dependencyGraph.swiftModuleDetails(of: mainModuleId)
+    return mainModuleDetails.contextHash
+  }
+
   /// Resolve all module dependencies of the main module and add them to the lists of
   /// inputs and command line flags.
   public mutating func resolveBridgingHeaderDependencies(inputs: inout [TypedVirtualPath],

Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift

@@ -101,6 +101,17 @@ extension Driver {
       jobNeedPathRemap = false
     }
 
+    // Check if dependency scanner has put the job into direct clang cc1 mode.
+    // If dependency scanner put us into direct cc1 mode, avoid adding `-Xcc` options, since
+    // dependency scanner already adds needed flags and -Xcc options known by swift-driver are
+    // clang driver flags but not it requires cc1 flags.
+    let directModuleCC1Mode = commandLine.contains(Job.ArgTemplate.flag("-direct-clang-cc1-module-build"))
+    func appendXccFlag(_ flag: String) {
+      guard !directModuleCC1Mode else { return }
+      commandLine.appendFlag(.Xcc)
+      commandLine.appendFlag(flag)
+    }
+
     if let variant = parsedOptions.getLastArgument(.targetVariant)?.asSingle {
       commandLine.appendFlag(.targetVariant)
       commandLine.appendFlag(Triple(variant, normalizing: true).triple)
@@ -125,8 +136,7 @@ extension Driver {
     try commandLine.appendLast(.enableExperimentalCxxInterop, from: &parsedOptions)
     try commandLine.appendLast(.cxxInteroperabilityMode, from: &parsedOptions)
     if let stdlibVariant = parsedOptions.getLastArgument(.experimentalCxxStdlib)?.asSingle {
-      commandLine.appendFlag("-Xcc")
-      commandLine.appendFlag("-stdlib=\(stdlibVariant)")
+      appendXccFlag("-stdlib=\(stdlibVariant)")
     }
 
     if isEmbeddedEnabled && parsedOptions.hasArgument(.enableLibraryEvolution) {
@@ -173,8 +183,7 @@ extension Driver {
     try commandLine.appendAll(.vfsoverlay, from: &parsedOptions)
 
     if let gccToolchain = parsedOptions.getLastArgument(.gccToolchain) {
-        commandLine.appendFlag(.Xcc)
-        commandLine.appendFlag("--gcc-toolchain=\(gccToolchain.asSingle)")
+        appendXccFlag("--gcc-toolchain=\(gccToolchain.asSingle)")
     }
 
     try commandLine.appendLast(.AssertConfig, from: &parsedOptions)
@@ -272,6 +281,11 @@ extension Driver {
     if isFrontendArgSupported(.strictConcurrency) {
       try commandLine.appendLast(.strictConcurrency, from: &parsedOptions)
     }
+    if kind == .scanDependencies,
+        isFrontendArgSupported(.experimentalClangImporterDirectCc1Scan) {
+      try commandLine.appendAll(
+        .experimentalClangImporterDirectCc1Scan, from: &parsedOptions)
+    }
 
     // Expand the -experimental-hermetic-seal-at-link flag
     if parsedOptions.hasArgument(.experimentalHermeticSealAtLink) {
@@ -332,7 +346,7 @@ extension Driver {
       try commandLine.appendLast(.disableSandbox, from: &parsedOptions)
     }
 
-    if !(isCachingEnabled && useClangIncludeTree), let workingDirectory = workingDirectory {
+    if !directModuleCC1Mode, let workingDirectory = workingDirectory {
       // Add -Xcc -working-directory before any other -Xcc options to ensure it is
       // overridden by an explicit -Xcc -working-directory, although having a
       // different working directory is probably incorrect.
@@ -402,8 +416,8 @@ extension Driver {
     // Pass through any subsystem flags.
     try commandLine.appendAll(.Xllvm, from: &parsedOptions)
 
-    // If using clang-include-tree, `-Xcc` should only be passed to scanDependencies job.
-    if (kind == .scanDependencies) || !(isCachingEnabled && useClangIncludeTree) {
+    // Pass through all -Xcc flags if not under directModuleCC1Mode.
+    if !directModuleCC1Mode {
       try commandLine.appendAll(.Xcc, from: &parsedOptions)
     }