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Merged
merged 2 commits into from
Aug 29, 2025
Merged

Dependencies: validate unused module dependencies #744

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2f15162
Dependencies: validate unused module dependencies
mirza-garibovic Aug 19, 2025
f1ba301
Dependencies: support optional module dependencies
mirza-garibovic Aug 20, 2025
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113 changes: 68 additions & 45 deletions Sources/SWBCore/Dependencies.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -76,35 +76,39 @@ public struct ModuleDependency: Hashable, Sendable, SerializableCodable {

public struct ModuleDependenciesContext: Sendable, SerializableCodable {
public var validate: BooleanWarningLevel
public var validateUnused: BooleanWarningLevel
var moduleDependencies: [ModuleDependency]
var fixItContext: FixItContext?

init(validate: BooleanWarningLevel, moduleDependencies: [ModuleDependency], fixItContext: FixItContext? = nil) {
init(validate: BooleanWarningLevel, validateUnused: BooleanWarningLevel, moduleDependencies: [ModuleDependency], fixItContext: FixItContext? = nil) {
self.validate = validate
self.validateUnused = validateUnused
self.moduleDependencies = moduleDependencies
self.fixItContext = fixItContext
}

public init?(settings: Settings) {
let validate = settings.globalScope.evaluate(BuiltinMacros.VALIDATE_MODULE_DEPENDENCIES)
guard validate != .no else { return nil }
let validateUnused = settings.globalScope.evaluate(BuiltinMacros.VALIDATE_UNUSED_MODULE_DEPENDENCIES)
guard validate != .no || validateUnused != .no else { return nil }
let downgrade = settings.globalScope.evaluate(BuiltinMacros.VALIDATE_DEPENDENCIES_DOWNGRADE_ERRORS)
let fixItContext = ModuleDependenciesContext.FixItContext(settings: settings)
self.init(validate: downgrade ? .yes : validate, moduleDependencies: settings.moduleDependencies, fixItContext: fixItContext)
let fixItContext = validate != .no ? ModuleDependenciesContext.FixItContext(settings: settings) : nil
self.init(validate: downgrade ? .yes : validate, validateUnused: validateUnused, moduleDependencies: settings.moduleDependencies, fixItContext: fixItContext)
}

public func makeUnsupportedToolchainDiagnostic() -> Diagnostic {
Diagnostic(
behavior: .warning,
location: .unknown,
data: DiagnosticData("The current toolchain does not support \(BuiltinMacros.VALIDATE_MODULE_DEPENDENCIES.name)"))
}

/// Compute missing module dependencies.
///
/// If `imports` is nil, the current toolchain does not support the features to gather imports.
public func computeMissingDependencies(
imports: [(ModuleDependency, importLocations: [Diagnostic.Location])]?,
imports: [(ModuleDependency, importLocations: [Diagnostic.Location])],
fromSwift: Bool
) -> [(ModuleDependency, importLocations: [Diagnostic.Location])]? {
) -> [(ModuleDependency, importLocations: [Diagnostic.Location])] {
guard validate != .no else { return [] }
guard let imports else {
return nil
}

return imports.filter {
// ignore module deps without source locations, these are inserted by swift / swift-build and we should treat them as implementation details which we can track without needing the user to declare them
if fromSwift && $0.importLocations.isEmpty { return false }
Expand All @@ -115,45 +119,63 @@ public struct ModuleDependenciesContext: Sendable, SerializableCodable {
}
}

/// Make diagnostics for missing module dependencies.
public func makeDiagnostics(missingDependencies: [(ModuleDependency, importLocations: [Diagnostic.Location])]?) -> [Diagnostic] {
guard let missingDependencies else {
return [Diagnostic(
behavior: .warning,
location: .unknown,
data: DiagnosticData("The current toolchain does not support \(BuiltinMacros.VALIDATE_MODULE_DEPENDENCIES.name)"))]
}

guard !missingDependencies.isEmpty else { return [] }
public func computeUnusedDependencies(usedModuleNames: Set<String>) -> [ModuleDependency] {
guard validateUnused != .no else { return [] }
return moduleDependencies.filter { !usedModuleNames.contains($0.name) }
}

let behavior: Diagnostic.Behavior = validate == .yesError ? .error : .warning
/// Make diagnostics for missing module dependencies.
public func makeDiagnostics(missingDependencies: [(ModuleDependency, importLocations: [Diagnostic.Location])], unusedDependencies: [ModuleDependency]) -> [Diagnostic] {
let missingDiagnostics: [Diagnostic]
if !missingDependencies.isEmpty {
let behavior: Diagnostic.Behavior = validate == .yesError ? .error : .warning

let fixIt = fixItContext?.makeFixIt(newModules: missingDependencies.map { $0.0 })
let fixIts = fixIt.map { [$0] } ?? []

let importDiags: [Diagnostic] = missingDependencies
.flatMap { dep in
dep.1.map {
return Diagnostic(
behavior: behavior,
location: $0,
data: DiagnosticData("Missing entry in \(BuiltinMacros.MODULE_DEPENDENCIES.name): \(dep.0.asBuildSettingEntryQuotedIfNeeded)"),
fixIts: fixIts)
}
}

let fixIt = fixItContext?.makeFixIt(newModules: missingDependencies.map { $0.0 })
let fixIts = fixIt.map { [$0] } ?? []
let message = "Missing entries in \(BuiltinMacros.MODULE_DEPENDENCIES.name): \(missingDependencies.map { $0.0.asBuildSettingEntryQuotedIfNeeded }.sorted().joined(separator: " "))"

let importDiags: [Diagnostic] = missingDependencies
.flatMap { dep in
dep.1.map {
return Diagnostic(
behavior: behavior,
location: $0,
data: DiagnosticData("Missing entry in \(BuiltinMacros.MODULE_DEPENDENCIES.name): \(dep.0.asBuildSettingEntryQuotedIfNeeded)"),
fixIts: fixIts)
}
}
let location: Diagnostic.Location = fixIt.map {
Diagnostic.Location.path($0.sourceRange.path, line: $0.sourceRange.endLine, column: $0.sourceRange.endColumn)
} ?? Diagnostic.Location.buildSetting(BuiltinMacros.MODULE_DEPENDENCIES)

let message = "Missing entries in \(BuiltinMacros.MODULE_DEPENDENCIES.name): \(missingDependencies.map { $0.0.asBuildSettingEntryQuotedIfNeeded }.sorted().joined(separator: " "))"
missingDiagnostics = [Diagnostic(
behavior: behavior,
location: location,
data: DiagnosticData(message),
fixIts: fixIts,
childDiagnostics: importDiags)]
}
else {
missingDiagnostics = []
}

let location: Diagnostic.Location = fixIt.map {
Diagnostic.Location.path($0.sourceRange.path, line: $0.sourceRange.endLine, column: $0.sourceRange.endColumn)
} ?? Diagnostic.Location.buildSetting(BuiltinMacros.MODULE_DEPENDENCIES)
let unusedDiagnostics: [Diagnostic]
if !unusedDependencies.isEmpty {
let message = "Unused entries in \(BuiltinMacros.MODULE_DEPENDENCIES.name): \(unusedDependencies.map { $0.name }.sorted().joined(separator: " "))"
// TODO location & fixit
unusedDiagnostics = [Diagnostic(
behavior: validateUnused == .yesError ? .error : .warning,
location: .unknown,
data: DiagnosticData(message),
fixIts: [])]
}
else {
unusedDiagnostics = []
}

return [Diagnostic(
behavior: behavior,
location: location,
data: DiagnosticData(message),
fixIts: fixIts,
childDiagnostics: importDiags)]
return missingDiagnostics + unusedDiagnostics
}

struct FixItContext: Sendable, SerializableCodable {
Expand All @@ -169,6 +191,7 @@ public struct ModuleDependenciesContext: Sendable, SerializableCodable {
guard let target = settings.target else { return nil }
let thisTargetCondition = MacroCondition(parameter: BuiltinMacros.targetNameCondition, valuePattern: target.name)

// TODO: if you have an assignment in a project-xcconfig and another assignment in target-settings, this would find the project-xcconfig assignment, but updating that might have no effect depending on the target-settings assignment
if let assignment = (settings.globalScope.table.lookupMacro(BuiltinMacros.MODULE_DEPENDENCIES)?.sequence.first {
$0.location != nil && ($0.conditions?.conditions == [thisTargetCondition] || ($0.conditions?.conditions.isEmpty ?? true))
}),
Expand Down
2 changes: 2 additions & 0 deletions Sources/SWBCore/Settings/BuiltinMacros.swift
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Expand Up @@ -1150,6 +1150,7 @@ public final class BuiltinMacros {
public static let VALIDATE_DEVELOPMENT_ASSET_PATHS = BuiltinMacros.declareEnumMacro("VALIDATE_DEVELOPMENT_ASSET_PATHS") as EnumMacroDeclaration<BooleanWarningLevel>
public static let VALIDATE_HEADER_DEPENDENCIES = BuiltinMacros.declareEnumMacro("VALIDATE_HEADER_DEPENDENCIES") as EnumMacroDeclaration<BooleanWarningLevel>
public static let VALIDATE_MODULE_DEPENDENCIES = BuiltinMacros.declareEnumMacro("VALIDATE_MODULE_DEPENDENCIES") as EnumMacroDeclaration<BooleanWarningLevel>
public static let VALIDATE_UNUSED_MODULE_DEPENDENCIES = BuiltinMacros.declareEnumMacro("VALIDATE_UNUSED_MODULE_DEPENDENCIES") as EnumMacroDeclaration<BooleanWarningLevel>
public static let VECTOR_SUFFIX = BuiltinMacros.declareStringMacro("VECTOR_SUFFIX")
public static let VERBOSE_PBXCP = BuiltinMacros.declareBooleanMacro("VERBOSE_PBXCP")
public static let VERSIONING_STUB = BuiltinMacros.declareStringMacro("VERSIONING_STUB")
Expand Down Expand Up @@ -2382,6 +2383,7 @@ public final class BuiltinMacros {
VALIDATE_DEVELOPMENT_ASSET_PATHS,
VALIDATE_HEADER_DEPENDENCIES,
VALIDATE_MODULE_DEPENDENCIES,
VALIDATE_UNUSED_MODULE_DEPENDENCIES,
VALID_ARCHS,
VECTOR_SUFFIX,
VERBOSE_PBXCP,
Expand Down
14 changes: 8 additions & 6 deletions Sources/SWBTaskExecution/TaskActions/ValidateDependenciesTaskAction.swift
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Expand Up @@ -66,17 +66,17 @@ public final class ValidateDependenciesTaskAction: TaskAction {

if let moduleContext = payload.moduleDependenciesContext {
if unsupported {
diagnostics.append(contentsOf: moduleContext.makeDiagnostics(missingDependencies: nil))
diagnostics.append(moduleContext.makeUnsupportedToolchainDiagnostic())
} else {
let clangMissingDeps = moduleContext.computeMissingDependencies(imports: allClangImports.map { ($0.dependency, $0.importLocations) }, fromSwift: false)
let swiftMissingDeps = moduleContext.computeMissingDependencies(imports: allSwiftImports.map { ($0.dependency, $0.importLocations) }, fromSwift: true)

// Update Swift dependencies with information from Clang dependencies on the same module.
var clangMissingDepsByName = [String: (ModuleDependency, importLocations: [Diagnostic.Location])]()
clangMissingDeps?.forEach {
clangMissingDeps.forEach {
clangMissingDepsByName[$0.0.name] = $0
}
let updatedSwiftMissingDeps: [(ModuleDependency, importLocations: [Diagnostic.Location])] = swiftMissingDeps?.map {
let updatedSwiftMissingDeps: [(ModuleDependency, importLocations: [Diagnostic.Location])] = swiftMissingDeps.map {
if let clangMissingDep = clangMissingDepsByName[$0.0.name] {
return (
ModuleDependency(name: $0.0.name, accessLevel: max($0.0.accessLevel, clangMissingDep.0.accessLevel)),
Expand All @@ -85,13 +85,15 @@ public final class ValidateDependenciesTaskAction: TaskAction {
} else {
return $0
}
} ?? []
}

// Filter missing C dependencies by known Swift dependencies to avoid duplicate diagnostics.
let swiftImports = Set(allSwiftImports.map { $0.dependency.name })
let uniqueClangMissingDeps = clangMissingDeps?.filter { !swiftImports.contains($0.0.name) } ?? []
let uniqueClangMissingDeps = clangMissingDeps.filter { !swiftImports.contains($0.0.name) }

let unusedDeps = moduleContext.computeUnusedDependencies(usedModuleNames: Set(allClangImports.map { $0.dependency.name } + allSwiftImports.map { $0.dependency.name }))

diagnostics.append(contentsOf: moduleContext.makeDiagnostics(missingDependencies: uniqueClangMissingDeps + updatedSwiftMissingDeps))
diagnostics.append(contentsOf: moduleContext.makeDiagnostics(missingDependencies: uniqueClangMissingDeps + updatedSwiftMissingDeps, unusedDependencies: unusedDeps))
}
}
if let headerContext = payload.headerDependenciesContext {
Expand Down
88 changes: 88 additions & 0 deletions Tests/SWBBuildSystemTests/DependencyValidationTests.swift
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Expand Up @@ -690,4 +690,92 @@ fileprivate struct DependencyValidationTests: CoreBasedTests {
}
}
}

@Test(.requireSDKs(.host), .requireClangFeatures(.printHeadersDirectPerFile), .skipHostOS(.windows, "toolchain too old"), .skipHostOS(.linux, "toolchain too old"))
func validateUnusedModuleDependencies() async throws {
try await withTemporaryDirectory { tmpDir in
let testWorkspace = try await TestWorkspace(
"Test",
sourceRoot: tmpDir.join("Test"),
projects: [
TestProject(
"Project",
groupTree: TestGroup(
"Sources",
children: [
TestFile("Swift.swift"),
TestFile("ObjC.m"),
TestFile("Project.xcconfig"),
]),
buildConfigurations: [TestBuildConfiguration(
"Debug",
baseConfig: "Project.xcconfig",
buildSettings: [
"PRODUCT_NAME": "$(TARGET_NAME)",
"CLANG_ENABLE_MODULES": "YES",
"CLANG_ENABLE_EXPLICIT_MODULES": "YES",
"SWIFT_ENABLE_EXPLICIT_MODULES": "YES",
"SWIFT_UPCOMING_FEATURE_INTERNAL_IMPORTS_BY_DEFAULT": "YES",
"SWIFT_VERSION": swiftVersion,
"DEFINES_MODULE": "YES",
"DSTROOT": tmpDir.join("dstroot").str,
"VALIDATE_MODULE_DEPENDENCIES": "YES_ERROR",
"VALIDATE_UNUSED_MODULE_DEPENDENCIES": "YES",
"SDKROOT": "$(HOST_PLATFORM)",
"SUPPORTED_PLATFORMS": "$(HOST_PLATFORM)",

// Temporarily override to use the latest toolchain in CI because we depend on swift and swift-driver changes which aren't in the baseline tools yet
"TOOLCHAINS": "swift",
// We still want to use the default clang since that is used to gate the test
"CC": defaultClangPath.str,
])],
targets: [
TestStandardTarget(
"TargetA",
type: .framework,
buildPhases: [
TestSourcesBuildPhase(["Swift.swift", "ObjC.m"]),
]),
]),
])

let tester = try await BuildOperationTester(getCore(), testWorkspace, simulated: false)

let swiftSourcePath = testWorkspace.sourceRoot.join("Project/Swift.swift")
try await tester.fs.writeFileContents(swiftSourcePath) { stream in
stream <<<
"""
import Foundation
"""
}

let objcSourcePath = testWorkspace.sourceRoot.join("Project/ObjC.m")
try await tester.fs.writeFileContents(objcSourcePath) { stream in
stream <<<
"""
#include <CoreFoundation/CoreFoundation.h>

void objcFunction(void) { }
"""
}

let projectXCConfigPath = testWorkspace.sourceRoot.join("Project/Project.xcconfig")
try await tester.fs.writeFileContents(projectXCConfigPath) { stream in
stream <<<
"""
MODULE_DEPENDENCIES[target=TargetA] = CoreFoundation Foundation AppKit
"""
}

let target = try #require(tester.workspace.projects.only?.targets.first { $0.name == "TargetA" })
let parameters = BuildParameters(configuration: "Debug")
let buildRequest = BuildRequest(parameters: parameters, buildTargets: [BuildRequest.BuildTargetInfo(parameters: parameters, target: target)], continueBuildingAfterErrors: false, useParallelTargets: true, useImplicitDependencies: true, useDryRun: false)

try await tester.checkBuild(runDestination: .host, buildRequest: buildRequest, persistent: true) { results in
guard !results.checkWarning(.prefix("The current toolchain does not support VALIDATE_MODULE_DEPENDENCIES"), failIfNotFound: false) else { return }

results.checkWarning(.contains("Unused entries in MODULE_DEPENDENCIES: AppKit"))
}
}
}
}