[Dependency Scanning] Remove references to per-triple PCM variant compilation

artemcm · artemcm · commit 072409a4c28c · 2025-01-29T16:39:26.000-08:00
diff --git a/Sources/CSwiftScan/include/swiftscan_header.h b/Sources/CSwiftScan/include/swiftscan_header.h
@@ -135,8 +135,6 @@ typedef struct {
   (*swiftscan_swift_textual_detail_get_command_line)(swiftscan_module_details_t);
   swiftscan_string_set_t *
   (*swiftscan_swift_textual_detail_get_bridging_pch_command_line)(swiftscan_module_details_t);
-  swiftscan_string_set_t *
-  (*swiftscan_swift_textual_detail_get_extra_pcm_args)(swiftscan_module_details_t);
   swiftscan_string_ref_t
   (*swiftscan_swift_textual_detail_get_context_hash)(swiftscan_module_details_t);
   bool
@@ -181,8 +179,6 @@ typedef struct {
   (*swiftscan_clang_detail_get_context_hash)(swiftscan_module_details_t);
   swiftscan_string_set_t *
   (*swiftscan_clang_detail_get_command_line)(swiftscan_module_details_t);
-  swiftscan_string_set_t *
-  (*swiftscan_clang_detail_get_captured_pcm_args)(swiftscan_module_details_t);
   swiftscan_string_ref_t
   (*swiftscan_clang_detail_get_module_cache_key)(swiftscan_module_details_t);
 
diff --git a/Sources/SwiftDriver/Driver/Driver.swift b/Sources/SwiftDriver/Driver/Driver.swift
@@ -70,7 +70,6 @@ public struct Driver {
     case optionRequiresAnother(String, String)
     // Explicit Module Build Failures
     case malformedModuleDependency(String, String)
-    case missingPCMArguments(String)
     case missingModuleDependency(String)
     case missingContextHashOnSwiftDependency(String)
     case dependencyScanningFailure(Int, String)
@@ -124,8 +123,6 @@ public struct Driver {
       // Explicit Module Build Failures
       case .malformedModuleDependency(let moduleName, let errorDescription):
         return "Malformed Module Dependency: \(moduleName), \(errorDescription)"
-      case .missingPCMArguments(let moduleName):
-        return "Missing extraPcmArgs to build Clang module: \(moduleName)"
       case .missingModuleDependency(let moduleName):
         return "Missing Module Dependency Info: \(moduleName)"
       case .missingContextHashOnSwiftDependency(let moduleName):
diff --git a/Sources/SwiftDriver/ExplicitModuleBuilds/ExplicitDependencyBuildPlanner.swift b/Sources/SwiftDriver/ExplicitModuleBuilds/ExplicitDependencyBuildPlanner.swift
@@ -193,8 +193,7 @@ public typealias ExternalTargetModuleDetailsMap = [ModuleDependencyId: ExternalT
     return jobs
   }
 
-  /// Generate a build job for each Clang module in the set of supplied `dependencies`. Once per each required
-  /// PCMArgSet as queried from the supplied `clangPCMSetMap`
+  /// Generate a build job for each Clang module in the set of supplied `dependencies`.
   private mutating func generateClangDependenciesBuildJobs(for dependencies: Set<ModuleDependencyId>)
   throws -> [Job] {
     var jobs: [Job] = []
@@ -391,25 +390,6 @@ public typealias ExternalTargetModuleDetailsMap = [ModuleDependencyId: ExternalT
     }
   }
 
-  private func updateClangPCMArgSetMap(for moduleId: ModuleDependencyId,
-                                       clangPCMSetMap: inout [ModuleDependencyId : Set<[String]>])
-  throws {
-    guard let moduleDependencies = reachabilityMap[moduleId] else {
-      fatalError("Expected reachability information for the module: \(moduleId.moduleName).")
-    }
-    let pcmArgs = try dependencyGraph.swiftModulePCMArgs(of: moduleId)
-    for dependencyId in moduleDependencies {
-      guard case .clang(_) = dependencyId else {
-        continue
-      }
-      if clangPCMSetMap[dependencyId] != nil {
-        clangPCMSetMap[dependencyId]!.insert(pcmArgs)
-      } else {
-        clangPCMSetMap[dependencyId] = [pcmArgs]
-      }
-    }
-  }
-
   public func getLinkLibraryLoadCommandFlags(_ commandLine: inout [Job.ArgTemplate]) throws {
     var allLinkLibraries: [LinkLibraryInfo] = []
     for (_, moduleInfo) in dependencyGraph.modules {
@@ -550,26 +530,6 @@ public typealias ExternalTargetModuleDetailsMap = [ModuleDependencyId: ExternalT
     encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
     return try encoder.encode(allDependencyArtifacts)
   }
-
-  private func getPCMHashParts(pcmArgs: [String], contextHash: String) -> [String] {
-    var results: [String] = []
-    results.append(contextHash)
-    results.append(contentsOf: pcmArgs)
-    if integratedDriver {
-      return results
-    }
-
-    // We need this to enable explicit modules in the driver-as-executable mode. For instance,
-    // we have two Swift targets A and B, where A depends on X.pcm which in turn depends on Y.pcm,
-    // and B only depends on Y.pcm. In the driver-as-executable mode, the build system isn't aware
-    // of the shared dependency of Y.pcm so it will be generated multiple times. If all these Y.pcm
-    // share the same name, X.pcm may fail to be loaded because its dependency Y.pcm may have a
-    // changed mod time.
-    // We only differentiate these PCM names in the non-integrated mode due to the lacking of
-    // inter-module planning.
-    results.append(mainModuleName!)
-    return results
-  }
 }
 
 /// Encapsulates some of the common queries of the ExplicitDependencyBuildPlanner with error-checking
@@ -605,11 +565,6 @@ public typealias ExternalTargetModuleDetailsMap = [ModuleDependencyId: ExternalT
     }
     return clangModuleDetails
   }
-
-  func swiftModulePCMArgs(of moduleId: ModuleDependencyId) throws -> [String] {
-    let moduleDetails = try swiftModuleDetails(of: moduleId)
-    return moduleDetails.extraPcmArgs
-  }
 }
 
 internal extension ExplicitDependencyBuildPlanner {
diff --git a/Sources/SwiftDriver/ExplicitModuleBuilds/InterModuleDependencies/CommonDependencyOperations.swift b/Sources/SwiftDriver/ExplicitModuleBuilds/InterModuleDependencies/CommonDependencyOperations.swift
@@ -117,67 +117,6 @@ extension InterModuleDependencyGraph {
 }
 
 @_spi(Testing) public extension InterModuleDependencyGraph {
-  /// Merge a module with a given ID and Info into a ModuleInfoMap
-  static func mergeModule(_ moduleId: ModuleDependencyId,
-                          _ moduleInfo: ModuleInfo,
-                          into moduleInfoMap: inout ModuleInfoMap) throws {
-    switch moduleId {
-      case .swift:
-        let prebuiltExternalModuleEquivalentId =
-          ModuleDependencyId.swiftPrebuiltExternal(moduleId.moduleName)
-        let placeholderEquivalentId =
-          ModuleDependencyId.swiftPlaceholder(moduleId.moduleName)
-        if moduleInfoMap[prebuiltExternalModuleEquivalentId] != nil ||
-            moduleInfoMap[moduleId] != nil {
-          // If the set of discovered externalModules contains a .swiftPrebuiltExternal or .swift module
-          // with the same name, do not replace it.
-          break
-        } else if moduleInfoMap[placeholderEquivalentId] != nil {
-          // Replace the placeholder module with a full .swift ModuleInfo
-          // and fixup other externalModules' dependencies
-          replaceModule(originalId: placeholderEquivalentId, replacementId: moduleId,
-                        replacementInfo: moduleInfo, in: &moduleInfoMap)
-        } else {
-          // Insert the new module
-          moduleInfoMap[moduleId] = moduleInfo
-        }
-
-      case .swiftPrebuiltExternal:
-        // If the set of discovered externalModules contains a .swift module with the same name,
-        // replace it with the prebuilt version and fixup other externalModules' dependencies
-        let swiftModuleEquivalentId = ModuleDependencyId.swift(moduleId.moduleName)
-        let swiftPlaceholderEquivalentId = ModuleDependencyId.swiftPlaceholder(moduleId.moduleName)
-        if moduleInfoMap[swiftModuleEquivalentId] != nil {
-          // If the ModuleInfoMap contains an equivalent .swift module, replace it with the prebuilt
-          // version and update all other externalModules' dependencies
-          replaceModule(originalId: swiftModuleEquivalentId, replacementId: moduleId,
-                        replacementInfo: moduleInfo, in: &moduleInfoMap)
-        } else if moduleInfoMap[swiftPlaceholderEquivalentId] != nil {
-          // If the moduleInfoMap contains an equivalent .swiftPlaceholder module, replace it with
-          // the prebuilt version and update all other externalModules' dependencies
-          replaceModule(originalId: swiftPlaceholderEquivalentId, replacementId: moduleId,
-                        replacementInfo: moduleInfo, in: &moduleInfoMap)
-        } else {
-          // Insert the new module
-          moduleInfoMap[moduleId] = moduleInfo
-        }
-
-      case .clang:
-        guard let existingModuleInfo = moduleInfoMap[moduleId] else {
-          moduleInfoMap[moduleId] = moduleInfo
-          break
-        }
-        // If this module *has* been seen before, merge the module infos to capture
-        // the super-set of so-far discovered dependencies of this module at various
-        // PCMArg scanning actions.
-        let combinedDependenciesInfo = mergeClangModuleInfoDependencies(moduleInfo,
-                                                                        existingModuleInfo)
-        replaceModule(originalId: moduleId, replacementId: moduleId,
-                      replacementInfo: combinedDependenciesInfo, in: &moduleInfoMap)
-      case .swiftPlaceholder:
-        fatalError("Unresolved placeholder dependency at graph merge operation: \(moduleId)")
-    }
-  }
 
   /// Replace an existing module in the moduleInfoMap
   static func replaceModule(originalId: ModuleDependencyId, replacementId: ModuleDependencyId,
@@ -207,53 +146,6 @@ extension InterModuleDependencyGraph {
       }
     }
   }
-
-  /// Given two moduleInfos of clang externalModules, merge them by combining their directDependencies and
-  /// dependenciesCapturedPCMArgs and sourceFiles fields. These fields may differ across the same module
-  /// scanned at different PCMArgs (e.g. -target option).
-  static func mergeClangModuleInfoDependencies(_ firstInfo: ModuleInfo, _ secondInfo:ModuleInfo
-  ) -> ModuleInfo {
-    guard case .clang(let firstDetails) = firstInfo.details,
-          case .clang(let secondDetails) = secondInfo.details
-    else {
-      fatalError("mergeClangModules expected two valid ClangModuleDetails objects.")
-    }
-
-    // As far as their dependencies go, these module infos are identical
-    if firstInfo.directDependencies == secondInfo.directDependencies,
-       firstDetails.capturedPCMArgs == secondDetails.capturedPCMArgs,
-       firstInfo.sourceFiles == secondInfo.sourceFiles {
-      return firstInfo
-    }
-
-    // Create a new moduleInfo that represents this module with combined dependency information
-    let firstModuleSources = firstInfo.sourceFiles ?? []
-    let secondModuleSources = secondInfo.sourceFiles ?? []
-    let combinedSourceFiles = Array(Set(firstModuleSources + secondModuleSources))
-
-    let firstModuleDependencies = firstInfo.directDependencies ?? []
-    let secondModuleDependencies = secondInfo.directDependencies ?? []
-    let combinedDependencies = Array(Set(firstModuleDependencies + secondModuleDependencies))
-    let firstLinkLibraries = firstInfo.linkLibraries ?? []
-    let secondLinkLibraries = secondInfo.linkLibraries ?? []
-    let combinedLinkLibraries = Array(Set(firstLinkLibraries + secondLinkLibraries))
-
-    let firstModuleCapturedPCMArgs = firstDetails.capturedPCMArgs ?? Set<[String]>()
-    let secondModuleCapturedPCMArgs = secondDetails.capturedPCMArgs ?? Set<[String]>()
-    let combinedCapturedPCMArgs = firstModuleCapturedPCMArgs.union(secondModuleCapturedPCMArgs)
-
-    let combinedModuleDetails =
-      ClangModuleDetails(moduleMapPath: firstDetails.moduleMapPath,
-                         contextHash: firstDetails.contextHash,
-                         commandLine: firstDetails.commandLine,
-                         capturedPCMArgs: combinedCapturedPCMArgs)
-
-    return ModuleInfo(modulePath: firstInfo.modulePath,
-                      sourceFiles: combinedSourceFiles,
-                      directDependencies: combinedDependencies,
-                      linkLibraries: combinedLinkLibraries,
-                      details: .clang(combinedModuleDetails))
-  }
 }
 
 /// Incremental Build Machinery
diff --git a/Sources/SwiftDriver/ExplicitModuleBuilds/InterModuleDependencies/InterModuleDependencyGraph.swift b/Sources/SwiftDriver/ExplicitModuleBuilds/InterModuleDependencies/InterModuleDependencyGraph.swift
@@ -132,11 +132,6 @@ public struct SwiftModuleDetails: Codable, Hashable {
   /// corresponding to the main module being built.
   public var contextHash: String?
 
-  /// To build a PCM to be used by this Swift module, we need to append these
-  /// arguments to the generic PCM build arguments reported from the dependency
-  /// graph.
-  public var extraPcmArgs: [String]
-
   /// A flag to indicate whether or not this module is a framework.
   public var isFramework: Bool?
 
@@ -192,10 +187,6 @@ public struct ClangModuleDetails: Codable, Hashable {
   /// Options to the compile command
   public var commandLine: [String] = []
 
-  /// Set of PCM Arguments of depending modules which
-  /// are covered by the directDependencies info of this module
-  public var capturedPCMArgs: Set<[String]>?
-
   /// The module cache key of the output module.
   public var moduleCacheKey: String?
 }
diff --git a/Sources/SwiftDriver/SwiftScan/DependencyGraphBuilder.swift b/Sources/SwiftDriver/SwiftScan/DependencyGraphBuilder.swift
@@ -178,10 +178,6 @@ private extension SwiftScan {
     let bridgingPchCommandLine = supportsBridgingHeaderPCHCommand ?
       try getOptionalStringArrayDetail(from: moduleDetailsRef,
                                        using: api.swiftscan_swift_textual_detail_get_bridging_pch_command_line) : nil
-    let extraPcmArgs =
-      try getStringArrayDetail(from: moduleDetailsRef,
-                               using: api.swiftscan_swift_textual_detail_get_extra_pcm_args,
-                               fieldName: "extraPCMArgs")
     let contextHash =
       try getOptionalStringDetail(from: moduleDetailsRef,
                           using: api.swiftscan_swift_textual_detail_get_context_hash)
@@ -206,7 +202,6 @@ private extension SwiftScan {
                               commandLine: commandLine,
                               bridgingPchCommandLine : bridgingPchCommandLine,
                               contextHash: contextHash,
-                              extraPcmArgs: extraPcmArgs,
                               isFramework: isFramework,
                               swiftOverlayDependencies: swiftOverlayDependencies,
                               moduleCacheKey: moduleCacheKey)
@@ -291,22 +286,12 @@ private extension SwiftScan {
                                using: api.swiftscan_clang_detail_get_command_line,
                                fieldName: "clang_detail.commandLine")
 
-    let capturedPCMArgs : Set<[String]>?
-    if clangDetailsHaveCapturedPCMArgs {
-      let capturedArgs = try getStringArrayDetail(from: moduleDetailsRef,
-                                                  using: api.swiftscan_clang_detail_get_captured_pcm_args,
-                                                  fieldName: "clang_detail.capturedPCMArgs")
-      capturedPCMArgs = [capturedArgs]
-    } else {
-      capturedPCMArgs = nil
-    }
     let moduleCacheKey = supportsCaching ? try getOptionalStringDetail(from: moduleDetailsRef,
                                                      using: api.swiftscan_clang_detail_get_module_cache_key) : nil
 
     return ClangModuleDetails(moduleMapPath: moduleMapPath,
                               contextHash: contextHash,
                               commandLine: commandLine,
-                              capturedPCMArgs: capturedPCMArgs,
                               moduleCacheKey: moduleCacheKey)
   }
 }
diff --git a/Sources/SwiftDriver/SwiftScan/SwiftScan.swift b/Sources/SwiftDriver/SwiftScan/SwiftScan.swift
@@ -229,10 +229,6 @@ private extension String {
     api.swiftscan_swift_binary_detail_get_header_dependency_module_dependencies != nil
   }
 
-  @_spi(Testing) public var clangDetailsHaveCapturedPCMArgs : Bool {
-    api.swiftscan_clang_detail_get_captured_pcm_args != nil
-  }
-
   @_spi(Testing) public var supportsBinaryModuleHeaderDependencies : Bool {
     return api.swiftscan_swift_binary_detail_get_header_dependencies != nil
   }
@@ -478,10 +474,6 @@ private extension swiftscan_functions_t {
     self.swiftscan_compiler_target_info_query_v2 =
       loadOptional("swiftscan_compiler_target_info_query_v2")
 
-    // Clang dependency captured PCM args
-    self.swiftscan_clang_detail_get_captured_pcm_args =
-      loadOptional("swiftscan_clang_detail_get_captured_pcm_args")
-
     // Scanner diagnostic emission query
     self.swiftscan_scanner_diagnostics_query =
       loadOptional("swiftscan_scanner_diagnostics_query")
@@ -657,8 +649,6 @@ private extension swiftscan_functions_t {
       try loadRequired("swiftscan_swift_textual_detail_get_bridging_module_dependencies")
     self.swiftscan_swift_textual_detail_get_command_line =
       try loadRequired("swiftscan_swift_textual_detail_get_command_line")
-    self.swiftscan_swift_textual_detail_get_extra_pcm_args =
-      try loadRequired("swiftscan_swift_textual_detail_get_extra_pcm_args")
     self.swiftscan_scan_invocation_get_argc =
       try loadRequired("swiftscan_scan_invocation_get_argc")
     self.swiftscan_scan_invocation_get_argv =
diff --git a/Tests/SwiftDriverTests/Inputs/ExplicitModuleDependencyBuildInputs.swift b/Tests/SwiftDriverTests/Inputs/ExplicitModuleDependencyBuildInputs.swift
