Centralize dependency diagnostics in ValidateDependencies action (#675)

Instead of emitting diagnostics directly, individual tasks emit .dependencies files which are read by a per-target action which aggregates them. This avoids duplication of diagnostics across tasks.

rdar://156174696

Author: neonichu

Sources/SWBCore/CMakeLists.txt

@@ -161,6 +161,7 @@ add_library(SWBCore
   SpecImplementations/Tools/TiffUtilTool.swift
   SpecImplementations/Tools/TouchTool.swift
   SpecImplementations/Tools/UnifdefTool.swift
+  SpecImplementations/Tools/ValidateDependencies.swift
   SpecImplementations/Tools/ValidateDevelopmentAssets.swift
   SpecImplementations/Tools/ValidateEmbeddedBinaryTool.swift
   SpecImplementations/Tools/ValidateProductTool.swift

Sources/SWBCore/Dependencies.swift

@@ -63,7 +63,7 @@ public struct ModuleDependency: Hashable, Sendable, SerializableCodable {
 }
 
 public struct ModuleDependenciesContext: Sendable, SerializableCodable {
-    var validate: BooleanWarningLevel
+    public var validate: BooleanWarningLevel
     var moduleDependencies: [ModuleDependency]
     var fixItContext: FixItContext?
 
@@ -235,3 +235,27 @@ public struct ModuleDependenciesContext: Sendable, SerializableCodable {
         }
     }
 }
+
+public struct DependencyValidationInfo: Hashable, Sendable, Codable {
+    public struct Import: Hashable, Sendable, Codable {
+        public let dependency: ModuleDependency
+        public let importLocations: [Diagnostic.Location]
+
+        public init(dependency: ModuleDependency, importLocations: [Diagnostic.Location]) {
+            self.dependency = dependency
+            self.importLocations = importLocations
+        }
+    }
+
+    public enum Payload: Hashable, Sendable, Codable {
+        case clangDependencies(files: [String])
+        case swiftDependencies(imports: [Import])
+        case unsupported
+    }
+
+    public let payload: Payload
+
+    public init(payload: Payload) {
+        self.payload = payload
+    }
+}

Sources/SWBCore/PlannedTaskAction.swift

@@ -346,6 +346,7 @@ public protocol TaskActionCreationDelegate
     func createSignatureCollectionTaskAction() -> any PlannedTaskAction
     func createClangModuleVerifierInputGeneratorTaskAction() -> any PlannedTaskAction
     func createProcessSDKImportsTaskAction() -> any PlannedTaskAction
+    func createValidateDependenciesTaskAction() -> any PlannedTaskAction
 }
 
 extension TaskActionCreationDelegate {

Sources/SWBCore/SpecImplementations/RegisterSpecs.swift

@@ -126,6 +126,7 @@ public struct BuiltinSpecsExtension: SpecificationsExtension {
             RegisterExecutionPolicyExceptionToolSpec.self,
             SwiftHeaderToolSpec.self,
             TAPIMergeToolSpec.self,
+            ValidateDependenciesSpec.self,
             ValidateDevelopmentAssets.self,
             ConstructStubExecutorFileListToolSpec.self,
             GateSpec.self,

Sources/SWBCore/SpecImplementations/Tools/CCompiler.swift

@@ -434,8 +434,9 @@ public struct ClangTaskPayload: ClangModuleVerifierPayloadType, DependencyInfoEd
 
     public let moduleDependenciesContext: ModuleDependenciesContext?
     public let traceFilePath: Path?
+    public let dependencyValidationOutputPath: Path?
 
-    fileprivate init(serializedDiagnosticsPath: Path?, indexingPayload: ClangIndexingPayload?, explicitModulesPayload: ClangExplicitModulesPayload? = nil, outputObjectFilePath: Path? = nil, fileNameMapPath: Path? = nil, developerPathString: String? = nil, moduleDependenciesContext: ModuleDependenciesContext? = nil, traceFilePath: Path? = nil) {
+    fileprivate init(serializedDiagnosticsPath: Path?, indexingPayload: ClangIndexingPayload?, explicitModulesPayload: ClangExplicitModulesPayload? = nil, outputObjectFilePath: Path? = nil, fileNameMapPath: Path? = nil, developerPathString: String? = nil, moduleDependenciesContext: ModuleDependenciesContext? = nil, traceFilePath: Path? = nil, dependencyValidationOutputPath: Path? = nil) {
         if let developerPathString, explicitModulesPayload == nil {
             self.dependencyInfoEditPayload = .init(removablePaths: [], removableBasenames: [], developerPath: Path(developerPathString))
         } else {
@@ -448,10 +449,11 @@ public struct ClangTaskPayload: ClangModuleVerifierPayloadType, DependencyInfoEd
         self.fileNameMapPath = fileNameMapPath
         self.moduleDependenciesContext = moduleDependenciesContext
         self.traceFilePath = traceFilePath
+        self.dependencyValidationOutputPath = dependencyValidationOutputPath
     }
 
     public func serialize<T: Serializer>(to serializer: T) {
-        serializer.serializeAggregate(8) {
+        serializer.serializeAggregate(9) {
             serializer.serialize(serializedDiagnosticsPath)
             serializer.serialize(indexingPayload)
             serializer.serialize(explicitModulesPayload)
@@ -460,11 +462,12 @@ public struct ClangTaskPayload: ClangModuleVerifierPayloadType, DependencyInfoEd
             serializer.serialize(dependencyInfoEditPayload)
             serializer.serialize(moduleDependenciesContext)
             serializer.serialize(traceFilePath)
+            serializer.serialize(dependencyValidationOutputPath)
         }
     }
 
     public init(from deserializer: any Deserializer) throws {
-        try deserializer.beginAggregate(8)
+        try deserializer.beginAggregate(9)
         self.serializedDiagnosticsPath = try deserializer.deserialize()
         self.indexingPayload = try deserializer.deserialize()
         self.explicitModulesPayload = try deserializer.deserialize()
@@ -473,6 +476,7 @@ public struct ClangTaskPayload: ClangModuleVerifierPayloadType, DependencyInfoEd
         self.dependencyInfoEditPayload = try deserializer.deserialize()
         self.moduleDependenciesContext = try deserializer.deserialize()
         self.traceFilePath = try deserializer.deserialize()
+        self.dependencyValidationOutputPath = try deserializer.deserialize()
     }
 }
 
@@ -1165,10 +1169,14 @@ public class ClangCompilerSpec : CompilerSpec, SpecIdentifierType, GCCCompatible
             dependencyData = nil
         }
 
+        let extraOutputs: [any PlannedNode]
         let moduleDependenciesContext = cbc.producer.moduleDependenciesContext
+        let dependencyValidationOutputPath: Path?
         let traceFilePath: Path?
         if clangInfo?.hasFeature("print-headers-direct-per-file") ?? false,
             (moduleDependenciesContext?.validate ?? .defaultValue) != .no {
+            dependencyValidationOutputPath = Path(outputNode.path.str + ".dependencies")
+
             let file = Path(outputNode.path.str + ".trace.json")
             commandLine += [
                 "-Xclang", "-header-include-file",
@@ -1177,8 +1185,12 @@ public class ClangCompilerSpec : CompilerSpec, SpecIdentifierType, GCCCompatible
                 "-Xclang", "-header-include-format=json"
             ]
             traceFilePath = file
+
+            extraOutputs = [MakePlannedPathNode(dependencyValidationOutputPath!), MakePlannedPathNode(traceFilePath!)]
         } else {
+            dependencyValidationOutputPath = nil
             traceFilePath = nil
+            extraOutputs = []
         }
 
         // Add the diagnostics serialization flag.  We currently place the diagnostics file right next to the output object file.
@@ -1293,7 +1305,8 @@ public class ClangCompilerSpec : CompilerSpec, SpecIdentifierType, GCCCompatible
             fileNameMapPath: verifierPayload?.fileNameMapPath,
             developerPathString: recordSystemHeaderDepsOutsideSysroot ? cbc.scope.evaluate(BuiltinMacros.DEVELOPER_DIR).str : nil,
             moduleDependenciesContext: moduleDependenciesContext,
-            traceFilePath: traceFilePath
+            traceFilePath: traceFilePath,
+            dependencyValidationOutputPath: dependencyValidationOutputPath
         )
 
         var inputNodes: [any PlannedNode] = inputDeps.map { delegate.createNode($0) }
@@ -1357,7 +1370,7 @@ public class ClangCompilerSpec : CompilerSpec, SpecIdentifierType, GCCCompatible
         }
 
         // Finally, create the task.
-        delegate.createTask(type: self, dependencyData: dependencyData, payload: payload, ruleInfo: ruleInfo, additionalSignatureData: additionalSignatureData, commandLine: commandLine, additionalOutput: additionalOutput, environment: environmentBindings, workingDirectory: compilerWorkingDirectory(cbc), inputs: inputNodes + extraInputs, outputs: [outputNode], action: action ?? delegate.taskActionCreationDelegate.createDeferredExecutionTaskActionIfRequested(userPreferences: cbc.producer.userPreferences), execDescription: resolveExecutionDescription(cbc, delegate), enableSandboxing: enableSandboxing, additionalTaskOrderingOptions: [.compilationForIndexableSourceFile], usesExecutionInputs: usesExecutionInputs, showEnvironment: true, priority: .preferred)
+        delegate.createTask(type: self, dependencyData: dependencyData, payload: payload, ruleInfo: ruleInfo, additionalSignatureData: additionalSignatureData, commandLine: commandLine, additionalOutput: additionalOutput, environment: environmentBindings, workingDirectory: compilerWorkingDirectory(cbc), inputs: inputNodes + extraInputs, outputs: [outputNode] + extraOutputs, action: action ?? delegate.taskActionCreationDelegate.createDeferredExecutionTaskActionIfRequested(userPreferences: cbc.producer.userPreferences), execDescription: resolveExecutionDescription(cbc, delegate), enableSandboxing: enableSandboxing, additionalTaskOrderingOptions: [.compilationForIndexableSourceFile], usesExecutionInputs: usesExecutionInputs, showEnvironment: true, priority: .preferred)
 
         // If the object file verifier is enabled and we are building with explicit modules, also create a job to produce adjacent objects using implicit modules, then compare the results.
         if cbc.scope.evaluate(BuiltinMacros.CLANG_ENABLE_EXPLICIT_MODULES_OBJECT_FILE_VERIFIER) && action != nil {

Sources/SWBCore/SpecImplementations/Tools/SwiftCompiler.swift

@@ -273,6 +273,16 @@ public struct SwiftSourceFileIndexingInfo: SourceFileIndexingInfo {
     }
 }
 
+public struct SwiftDependencyValidationPayload: SerializableCodable, Encodable, Sendable {
+    public let dependencyValidationOutputPath: Path
+    public let moduleDependenciesContext: ModuleDependenciesContext
+
+    public init(dependencyValidationOutputPath: Path, moduleDependenciesContext: ModuleDependenciesContext) {
+        self.dependencyValidationOutputPath = dependencyValidationOutputPath
+        self.moduleDependenciesContext = moduleDependenciesContext
+    }
+}
+
 /// The minimal data we need to serialize to reconstruct `generatePreviewInfo`
 public struct SwiftPreviewPayload: Serializable, Encodable, Sendable {
     public let architecture: String
@@ -446,9 +456,9 @@ public struct SwiftTaskPayload: ParentTaskPayload {
     /// The preview build style in effect (dynamic replacement or XOJIT), if any.
     public let previewStyle: PreviewStyleMessagePayload?
 
-    public let moduleDependenciesContext: ModuleDependenciesContext?
+    public let dependencyValidationPayload: SwiftDependencyValidationPayload?
 
-    init(moduleName: String, indexingPayload: SwiftIndexingPayload, previewPayload: SwiftPreviewPayload?, localizationPayload: SwiftLocalizationPayload?, numExpectedCompileSubtasks: Int, driverPayload: SwiftDriverPayload?, previewStyle: PreviewStyle?, moduleDependenciesContext: ModuleDependenciesContext?) {
+    init(moduleName: String, indexingPayload: SwiftIndexingPayload, previewPayload: SwiftPreviewPayload?, localizationPayload: SwiftLocalizationPayload?, numExpectedCompileSubtasks: Int, driverPayload: SwiftDriverPayload?, previewStyle: PreviewStyle?, dependencyValidationPayload: SwiftDependencyValidationPayload?) {
         self.moduleName = moduleName
         self.indexingPayload = indexingPayload
         self.previewPayload = previewPayload
@@ -463,7 +473,7 @@ public struct SwiftTaskPayload: ParentTaskPayload {
         case nil:
             self.previewStyle = nil
         }
-        self.moduleDependenciesContext = moduleDependenciesContext
+        self.dependencyValidationPayload = dependencyValidationPayload
     }
 
     public func serialize<T: Serializer>(to serializer: T) {
@@ -475,7 +485,7 @@ public struct SwiftTaskPayload: ParentTaskPayload {
             serializer.serialize(numExpectedCompileSubtasks)
             serializer.serialize(driverPayload)
             serializer.serialize(previewStyle)
-            serializer.serialize(moduleDependenciesContext)
+            serializer.serialize(dependencyValidationPayload)
         }
     }
 
@@ -488,7 +498,7 @@ public struct SwiftTaskPayload: ParentTaskPayload {
         self.numExpectedCompileSubtasks = try deserializer.deserialize()
         self.driverPayload = try deserializer.deserialize()
         self.previewStyle = try deserializer.deserialize()
-        self.moduleDependenciesContext = try deserializer.deserialize()
+        self.dependencyValidationPayload = try deserializer.deserialize()
     }
 }
 
@@ -2283,6 +2293,20 @@ public final class SwiftCompilerSpec : CompilerSpec, SpecIdentifierType, SwiftDi
                 moduleOutputPaths.append(moduleWrapOutput)
             }
 
+            let dependencyValidationPayload: SwiftDependencyValidationPayload?
+            if let context = cbc.producer.moduleDependenciesContext, let outputPath = objectOutputPaths.first, context.validate != .no {
+                let primarySwiftBaseName = cbc.scope.evaluate(BuiltinMacros.TARGET_NAME) + compilationMode.moduleBaseNameSuffix + "-primary"
+                let dependencyValidationOutputPath = outputPath.dirname.join(primarySwiftBaseName + ".dependencies")
+                extraOutputPaths.append(dependencyValidationOutputPath)
+
+                dependencyValidationPayload = .init(
+                    dependencyValidationOutputPath: dependencyValidationOutputPath,
+                    moduleDependenciesContext: context
+                )
+            } else {
+                dependencyValidationPayload = nil
+            }
+
             // The rule info.
             //
             // NOTE: If this changes, be sure to update the log parser to extract the variant and arch properly.
@@ -2312,7 +2336,7 @@ public final class SwiftCompilerSpec : CompilerSpec, SpecIdentifierType, SwiftDi
                 numExpectedCompileSubtasks: isUsingWholeModuleOptimization ? 1 : cbc.inputs.count,
                 driverPayload: await driverPayload(uniqueID: String(args.hashValue), scope: cbc.scope, delegate: delegate, compilationMode: compilationMode, isUsingWholeModuleOptimization: isUsingWholeModuleOptimization, args: args, tempDirPath: objectFileDir, explicitModulesTempDirPath: Path(cbc.scope.evaluate(BuiltinMacros.SWIFT_EXPLICIT_MODULES_OUTPUT_PATH)), variant: variant, arch: arch + compilationMode.moduleBaseNameSuffix, commandLine: ["builtin-SwiftDriver", "--"] + args, ruleInfo: ruleInfo(compilationMode.ruleNameIntegratedDriver, targetName), casOptions: casOptions, linkerResponseFilePath: moduleLinkerArgsPath),
                 previewStyle: cbc.scope.previewStyle,
-                moduleDependenciesContext: cbc.producer.moduleDependenciesContext
+                dependencyValidationPayload: dependencyValidationPayload
             )
 
             // Finally, assemble the input and output paths and create the Swift compiler command.

Sources/SWBCore/SpecImplementations/Tools/ValidateDependencies.swift

@@ -0,0 +1,53 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+public import SWBUtil
+import SWBMacro
+
+public final class ValidateDependenciesSpec: CommandLineToolSpec, SpecImplementationType, @unchecked Sendable {
+    public static let identifier = "com.apple.tools.validate-dependencies"
+
+    public static func construct(registry: SpecRegistry, proxy: SpecProxy) -> Spec {
+        return ValidateDependenciesSpec(registry: registry)
+    }
+
+    public init(registry: SpecRegistry) {
+        let proxy = SpecProxy(identifier: Self.identifier, domain: "", path: Path(""), type: Self.self, classType: nil, basedOn: nil, data: ["ExecDescription": PropertyListItem("Validate dependencies")], localizedStrings: nil)
+        super.init(createSpecParser(for: proxy, registry: registry), nil, isGeneric: false)
+    }
+
+    required init(_ parser: SpecParser, _ basedOnSpec: Spec?) {
+        super.init(parser, basedOnSpec, isGeneric: false)
+    }
+
+    override public func constructTasks(_ cbc: CommandBuildContext, _ delegate: any TaskGenerationDelegate) async {
+        fatalError("unexpected direct invocation")
+    }
+
+    public override var payloadType: (any TaskPayload.Type)? { return ValidateDependenciesPayload.self }
+
+    public func createTasks(_ cbc: CommandBuildContext, _ delegate: any TaskGenerationDelegate, dependencyInfos: [PlannedPathNode], payload: ValidateDependenciesPayload) async {
+        guard let configuredTarget = cbc.producer.configuredTarget else {
+            return
+        }
+        let output =  delegate.createVirtualNode("ValidateDependencies \(configuredTarget.guid)")
+        delegate.createTask(type: self, payload: payload, ruleInfo: ["ValidateDependencies"], commandLine: ["builtin-validate-dependencies"] + dependencyInfos.map { $0.path.str }, environment: EnvironmentBindings(), workingDirectory: cbc.producer.defaultWorkingDirectory, inputs: dependencyInfos + cbc.commandOrderingInputs, outputs: [output], action: delegate.taskActionCreationDelegate.createValidateDependenciesTaskAction(), preparesForIndexing: false, enableSandboxing: false)
+    }
+}
+
+public struct ValidateDependenciesPayload: TaskPayload, Sendable, SerializableCodable {
+    public let moduleDependenciesContext: ModuleDependenciesContext
+
+    public init(moduleDependenciesContext: ModuleDependenciesContext) {
+        self.moduleDependenciesContext = moduleDependenciesContext
+    }
+}

Sources/SWBCore/TaskGeneration.swift

@@ -189,6 +189,8 @@ public protocol CommandProducer: PlatformBuildContext, SpecLookupContext, Refere
 
     var processSDKImportsSpec: ProcessSDKImportsSpec { get }
 
+    var validateDependenciesSpec: ValidateDependenciesSpec { get }
+
     /// The default working directory to use for a task, if it doesn't have a stronger preference.
     var defaultWorkingDirectory: Path { get }
 

Sources/SWBTaskConstruction/TaskProducers/BuildPhaseTaskProducers/SourcesTaskProducer.swift

@@ -758,6 +758,7 @@ final class SourcesTaskProducer: FilesBasedBuildPhaseTaskProducerBase, FilesBase
         }
 
         var tasks: [any PlannedTask] = []
+        var dependencyDataFiles: [PlannedPathNode] = []
 
         // Generate any auxiliary files whose content is not per-arch or per-variant.
         // For the index build arena it is important to avoid adding this because it forces creation of the Swift module due to the generated ObjC header being an input dependency. This is unnecessary work since we don't need to generate the Swift module of the target to be able to successfully create a compiler AST for the Swift files of the target.
@@ -903,6 +904,8 @@ final class SourcesTaskProducer: FilesBasedBuildPhaseTaskProducerBase, FilesBase
                         case "swiftmodule":
                             dsymutilInputNodes.append(object)
                             break
+                        case "dependencies":
+                            dependencyDataFiles.append(MakePlannedPathNode(object.path))
                         default:
                             break
                         }
@@ -1594,6 +1597,20 @@ final class SourcesTaskProducer: FilesBasedBuildPhaseTaskProducerBase, FilesBase
             tasks = tasks.filter { $0.inputs.contains(where: { $0.path.isValidLocalizedContent(scope) || $0.path.fileExtension == "xcstrings" }) }
         }
 
+        // Create a task to validate dependencies if that feature is enabled.
+        if let moduleDependenciesContext = context.moduleDependenciesContext, moduleDependenciesContext.validate != .no {
+            var validateDepsTasks = [any PlannedTask]()
+            await appendGeneratedTasks(&validateDepsTasks, usePhasedOrdering: true) { delegate in
+                await context.validateDependenciesSpec.createTasks(
+                    CommandBuildContext(producer: context, scope: scope, inputs: []),
+                    delegate,
+                    dependencyInfos: dependencyDataFiles,
+                    payload: .init(moduleDependenciesContext: moduleDependenciesContext)
+                )
+            }
+            tasks.append(contentsOf: validateDepsTasks)
+        }
+
         return tasks
     }