swiftlang · artemcm · Jul 12, 2021 · Jul 7, 2021
diff --git a/Sources/SwiftDriver/CMakeLists.txt b/Sources/SwiftDriver/CMakeLists.txt
@@ -10,7 +10,6 @@ add_library(SwiftDriver
   "ExplicitModuleBuilds/ClangVersionedDependencyResolution.swift"
   "ExplicitModuleBuilds/ExplicitDependencyBuildPlanner.swift"
   "ExplicitModuleBuilds/ModuleDependencyScanning.swift"
-  "ExplicitModuleBuilds/PlaceholderDependencyResolution.swift"
   "ExplicitModuleBuilds/SerializableModuleArtifacts.swift"
   "ExplicitModuleBuilds/InterModuleDependencies/CommonDependencyOperations.swift"
   "ExplicitModuleBuilds/InterModuleDependencies/InterModuleDependencyGraph.swift"

diff --git a/Sources/SwiftDriver/Driver/Driver.swift b/Sources/SwiftDriver/Driver/Driver.swift
@@ -305,12 +305,9 @@ public struct Driver {
   /// is shared across many targets; otherwise, a new instance is created by the driver itself.
   @_spi(Testing) public let interModuleDependencyOracle: InterModuleDependencyOracle
 
-  // TODO: Once the clients have transitioned to using the InterModuleDependencyOracle API,
-  // this must convey information about the externally-prebuilt targets only
-  /// All external artifacts a build system (e.g. SwiftPM) may pass in as input to the explicit
-  /// build of the current module. Consists of a map of externally-built targets, and a map of all previously
-  /// discovered/scanned modules and their infos.
-  @_spi(Testing) public var externalBuildArtifacts: ExternalBuildArtifacts? = nil
+  /// A dictionary of external targets that are a part of the same build, mapping to filesystem paths
+  /// of their module files
+  @_spi(Testing) public var externalTargetModulePathMap: ExternalTargetModulePathMap? = nil
 
   /// A collection of all the flags the selected toolchain's `swift-frontend` supports
   public let supportedFrontendFlags: Set<String>
@@ -387,9 +384,14 @@ public struct Driver {
   ///   expand response files, etc. By default this is the local filesystem.
   /// - Parameter executor: Used by the driver to execute jobs. The default argument
   ///   is present to streamline testing, it shouldn't be used in production.
-  /// - Parameter externalBuildArtifacts: All external artifacts a build system may pass in as input to the explicit
-  ///   build of the current module. Consists of a map of externally-built targets, and a map of all previously
-  ///   discovered/scanned modules.
+  /// - Parameter integratedDriver: Used to distinguish whether the driver is being used as
+  ///   an executable or as a library.
+  /// - Parameter compilerExecutableDir: Directory that contains the compiler executable to be used.
+  ///   Used when in `integratedDriver` mode as a substitute for the driver knowing its executable path.
+  /// - Parameter externalTargetModulePathMap: A dictionary of external targets that are a part of
+  ///   the same build, mapping to filesystem paths of their module files.
+  /// - Parameter interModuleDependencyOracle: An oracle for querying inter-module dependencies,
+  ///   shared across different module builds by a build system.
   public init(
     args: [String],
     env: [String: String] = ProcessEnv.vars,
@@ -398,9 +400,6 @@ public struct Driver {
     executor: DriverExecutor,
     integratedDriver: Bool = true,
     compilerExecutableDir: AbsolutePath? = nil,
-    // FIXME: Duplication with externalBuildArtifacts and externalTargetModulePathMap
-    // is a temporary backwards-compatibility shim to help transition SwiftPM to the new API
-    externalBuildArtifacts: ExternalBuildArtifacts? = nil,
     externalTargetModulePathMap: ExternalTargetModulePathMap? = nil,
     interModuleDependencyOracle: InterModuleDependencyOracle? = nil
   ) throws {
@@ -411,10 +410,8 @@ public struct Driver {
     self.diagnosticEngine = diagnosticsEngine
     self.executor = executor
 
-    if let externalArtifacts = externalBuildArtifacts {
-      self.externalBuildArtifacts = externalArtifacts
-    } else if let externalTargetPaths = externalTargetModulePathMap {
-      self.externalBuildArtifacts = (externalTargetPaths, [:])
+    if let externalTargetPaths = externalTargetModulePathMap {
+      self.externalTargetModulePathMap = externalTargetPaths
     }
 
     if case .subcommand = try Self.invocationRunMode(forArgs: args).mode {
@@ -507,14 +504,6 @@ public struct Driver {
       self.interModuleDependencyOracle = dependencyOracle
     } else {
       self.interModuleDependencyOracle = InterModuleDependencyOracle()
-
-      // This is a shim for backwards-compatibility with ModuleInfoMap-based API
-      // used by SwiftPM
-      if let externalArtifacts = externalBuildArtifacts {
-        if !externalArtifacts.1.isEmpty {
-          try self.interModuleDependencyOracle.mergeModules(from: externalArtifacts.1)
-        }
-      }
     }
 
     self.fileListThreshold = try Self.computeFileListThreshold(&self.parsedOptions, diagnosticsEngine: diagnosticsEngine)

diff --git a/Sources/SwiftDriver/ExplicitModuleBuilds/ExplicitDependencyBuildPlanner.swift b/Sources/SwiftDriver/ExplicitModuleBuilds/ExplicitDependencyBuildPlanner.swift
@@ -16,12 +16,6 @@ import Foundation
 /// A map from a module identifier to a path to its .swiftmodule file.
 public typealias ExternalTargetModulePathMap = [ModuleDependencyId: AbsolutePath]
 
-// FIXME: ExternalBuildArtifacts is a temporary backwards-compatibility shim
-// to help transition SwiftPM to the new API.
-/// A tuple all external artifacts a build system may pass in as input to the explicit build of the current module
-/// Consists of a map of externally-built targets, and a map of all previously discovered/scanned modules.
-public typealias ExternalBuildArtifacts = (ExternalTargetModulePathMap, ModuleInfoMap)
-
 /// In Explicit Module Build mode, this planner is responsible for generating and providing
 /// build jobs for all module dependencies and providing compile command options
 /// that specify said explicit module dependencies.
@@ -444,7 +438,7 @@ extension ExplicitDependencyBuildPlanner {
 
 /// Encapsulates some of the common queries of the ExplicitDependencyBuildPlanner with error-checking
 /// on the dependency graph's structure.
-internal extension InterModuleDependencyGraph {
+@_spi(Testing) public extension InterModuleDependencyGraph {
   func moduleInfo(of moduleId: ModuleDependencyId) throws -> ModuleInfo {
     guard let moduleInfo = modules[moduleId] else {
       throw Driver.Error.missingModuleDependency(moduleId.moduleName)

diff --git a/...SwiftDriver/ExplicitModuleBuilds/InterModuleDependencies/CommonDependencyOperations.swift b/...SwiftDriver/ExplicitModuleBuilds/InterModuleDependencies/CommonDependencyOperations.swift
@@ -15,11 +15,9 @@ import TSCBasic
   /// For targets that are built alongside the driver's current module, the scanning action will report them as
   /// textual targets to be built from source. Because we can rely on these targets to have been built prior
   /// to the driver's current target, we resolve such external targets as prebuilt binary modules, in the graph.
-  mutating func resolveExternalDependencies(for externalBuildArtifacts: ExternalBuildArtifacts)
+  mutating func resolveExternalDependencies(for externalTargetModulePathMap: ExternalTargetModulePathMap)
   throws {
-    let externalTargetModulePathMap = externalBuildArtifacts.0
-
-     for (externalModuleId, externalModulePath) in externalTargetModulePathMap {
+    for (externalModuleId, externalModulePath) in externalTargetModulePathMap {
       // Replace the occurence of a Swift module to-be-built from source-file
       // to an info that describes a pre-built binary module.
       let swiftModuleId: ModuleDependencyId = .swift(externalModuleId.moduleName)
@@ -30,57 +28,22 @@ import TSCBasic
         // a dependency on a target that is not actually used.
         continue
       }
-
-       let newModuleId: ModuleDependencyId = .swiftPrebuiltExternal(externalModuleId.moduleName)
+      
+      let newModuleId: ModuleDependencyId = .swiftPrebuiltExternal(externalModuleId.moduleName)
       let newExternalModuleDetails =
-        try SwiftPrebuiltExternalModuleDetails(compiledModulePath:
-                                                TextualVirtualPath(path: VirtualPath.absolute(externalModulePath).intern()))
+      try SwiftPrebuiltExternalModuleDetails(compiledModulePath:
+                                              TextualVirtualPath(path: VirtualPath.absolute(externalModulePath).intern()))
       let newInfo = ModuleInfo(modulePath: TextualVirtualPath(path: VirtualPath.absolute(externalModulePath).intern()),
                                sourceFiles: [],
                                directDependencies: currentInfo.directDependencies,
                                details: .swiftPrebuiltExternal(newExternalModuleDetails))
 
-       Self.replaceModule(originalId: swiftModuleId, replacementId: newModuleId,
+      Self.replaceModule(originalId: swiftModuleId, replacementId: newModuleId,
                          replacementInfo: newInfo, in: &modules)
     }
   }
 }
 
-@_spi(Testing) public extension InterModuleDependencyOracle {
-  /// An API to allow clients to accumulate InterModuleDependencyGraphs across mutiple main externalModules/targets
-  /// into a single collection of discovered externalModules.
-  func mergeModules(from dependencyGraph: InterModuleDependencyGraph) throws {
-    try queue.sync {
-      for (moduleId, moduleInfo) in dependencyGraph.modules {
-        try InterModuleDependencyGraph.mergeModule(moduleId, moduleInfo, into: &externalModules)
-      }
-    }
-  }
-
-  // This is a backwards-compatibility shim to handle existing ModuleInfoMap-based API
-  // used by SwiftPM
-  func mergeModules(from moduleInfoMap: ModuleInfoMap) throws {
-    try queue.sync {
-      for (moduleId, moduleInfo) in moduleInfoMap {
-        try InterModuleDependencyGraph.mergeModule(moduleId, moduleInfo, into: &externalModules)
-      }
-    }
-  }
-}
-
-public extension InterModuleDependencyGraph {
-  // This is a shim for backwards-compatibility with existing API used by SwiftPM.
-  // TODO: After SwiftPM switches to using the oracle, this should be deleted.
-  static func mergeModules(
-    from dependencyGraph: InterModuleDependencyGraph,
-    into discoveredModules: inout ModuleInfoMap
-  ) throws {
-    for (moduleId, moduleInfo) in dependencyGraph.modules {
-      try mergeModule(moduleId, moduleInfo, into: &discoveredModules)
-    }
-  }
-}
-
 extension InterModuleDependencyGraph {
   /// Compute a set of modules that are "reachable" (form direct or transitive dependency)
   /// from each module in the graph.

diff --git a/...wiftDriver/ExplicitModuleBuilds/InterModuleDependencies/InterModuleDependencyOracle.swift b/...wiftDriver/ExplicitModuleBuilds/InterModuleDependencies/InterModuleDependencyOracle.swift
@@ -118,44 +118,5 @@ public class InterModuleDependencyOracle {
 
   /// A reference to an instance of the compiler's libSwiftScan shared library
   private var swiftScanLibInstance: SwiftScan? = nil
-
-  // The below API is a legacy implementation of the oracle that is in-place to allow clients to
-  // transition to the new API. It is to be removed once that transition is complete.
-  /// The complete set of modules discovered so far, spanning potentially multiple targets,
-  /// accumulated across builds of multiple targets.
-  /// TODO: This is currently only used for placeholder resolution. libSwiftScan should allow us to move away
-  /// from the concept of a placeholder module so we should be able to get rid of this in the future.
-  internal var externalModules: ModuleInfoMap = [:]
-  /// Query the ModuleInfo of a module with a given ID
-  @_spi(Testing) public func getExternalModuleInfo(of moduleId: ModuleDependencyId) -> ModuleInfo? {
-    queue.sync {
-      return externalModules[moduleId]
-    }
-  }
 }
 
-// This is a shim for backwards-compatibility with existing API used by SwiftPM.
-// TODO: After SwiftPM switches to using the oracle, this should be deleted.
-extension Driver {
-  public var interModuleDependencyGraph: InterModuleDependencyGraph? {
-    let mainModuleId : ModuleDependencyId = .swift(moduleOutputInfo.name)
-    var mainModuleDependencyGraph =
-      InterModuleDependencyGraph(mainModuleName: moduleOutputInfo.name)
-
-    addModule(moduleId: mainModuleId,
-              moduleInfo: interModuleDependencyOracle.getExternalModuleInfo(of: mainModuleId)!,
-              into: &mainModuleDependencyGraph)
-    return mainModuleDependencyGraph
-  }
-
-  private func addModule(moduleId: ModuleDependencyId,
-                         moduleInfo: ModuleInfo,
-                         into dependencyGraph: inout InterModuleDependencyGraph) {
-    dependencyGraph.modules[moduleId] = moduleInfo
-    moduleInfo.directDependencies?.forEach { dependencyId in
-      addModule(moduleId: dependencyId,
-                moduleInfo: interModuleDependencyOracle.getExternalModuleInfo(of: dependencyId)!,
-                into: &dependencyGraph)
-    }
-  }
-}
diff --git a/Sources/SwiftDriver/ExplicitModuleBuilds/ModuleDependencyScanning.swift b/Sources/SwiftDriver/ExplicitModuleBuilds/ModuleDependencyScanning.swift
@@ -52,48 +52,11 @@ public extension Driver {
                                  moduleDependencyGraphUse: .dependencyScan)
     // FIXME: MSVC runtime flags
 
-    // Pass in external target dependencies to be treated as placeholder dependencies by the scanner
-    if let externalBuildArtifacts = externalBuildArtifacts {
-      let dependencyPlaceholderMapFile =
-        try serializeExternalDependencyArtifacts(externalBuildArtifacts: externalBuildArtifacts)
-      commandLine.appendFlag("-placeholder-dependency-module-map-file")
-      commandLine.appendPath(dependencyPlaceholderMapFile)
-    }
-
     // Pass on the input files
     commandLine.append(contentsOf: inputFiles.map { .path($0.file) })
     return (inputs, commandLine)
   }
 
-  /// Serialize a map of placeholder (external) dependencies for the dependency scanner.
-  private func serializeExternalDependencyArtifacts(externalBuildArtifacts: ExternalBuildArtifacts)
-  throws -> VirtualPath {
-    let (externalTargetModulePathMap, externalModuleInfoMap)  = externalBuildArtifacts
-    var placeholderArtifacts: [SwiftModuleArtifactInfo] = []
-
-    // Explicit external targets
-    for (moduleId, binaryModulePath) in externalTargetModulePathMap {
-      let modPath = TextualVirtualPath(path: VirtualPath.absolute(binaryModulePath).intern())
-      placeholderArtifacts.append(
-          SwiftModuleArtifactInfo(name: moduleId.moduleName,
-                                  modulePath: modPath))
-    }
-
-    // All other already-scanned Swift modules
-    for (moduleId, moduleInfo) in externalModuleInfoMap
-    where !externalTargetModulePathMap.keys.contains(moduleId) {
-      guard case .swift(_) = moduleId else { continue }
-      placeholderArtifacts.append(
-          SwiftModuleArtifactInfo(name: moduleId.moduleName,
-                                  modulePath: moduleInfo.modulePath))
-    }
-    let encoder = JSONEncoder()
-    encoder.outputFormatting = [.prettyPrinted]
-    let contents = try encoder.encode(placeholderArtifacts)
-    return VirtualPath.createUniqueTemporaryFileWithKnownContents(.init("\(moduleOutputInfo.name)-placeholder-modules.json"),
-                                                                  contents)
-  }
-
   /// Returns false if the lib is available and ready to use
   private func initSwiftScanLib() throws -> Bool {
     // If `-nonlib-dependency-scanner` was specified or the libSwiftScan library cannot be found,