Default Package Settings

Sources/PackageLoading/ManifestJSONParser.swift

@@ -38,6 +38,10 @@ enum ManifestJSONParser {
     struct Result {
         var name: String
         var defaultLocalization: String?
+        var defaultSwiftSettings: [TargetBuildSettingDescription.Setting]? = []
+        var defaultCSettings: [TargetBuildSettingDescription.Setting]? = []
+        var defaultCXXSettings: [TargetBuildSettingDescription.Setting]? = []
+        var defaultLinkerSettings: [TargetBuildSettingDescription.Setting]? = []
         var platforms: [PlatformDescription] = []
         var targets: [TargetDescription] = []
         var pkgConfig: String?
@@ -107,6 +111,10 @@ enum ManifestJSONParser {
         return Result(
             name: input.package.name,
             defaultLocalization: input.package.defaultLocalization?.tag,
+            defaultSwiftSettings: try input.package.defaultSwiftSettings?.map { try .init($0) },
+            defaultCSettings: try input.package.defaultCSettings?.map { try .init($0) },
+            defaultCXXSettings: try input.package.defaultCXXSettings?.map { try .init($0) },
+            defaultLinkerSettings: try input.package.defaultLinkerSettings?.map { try .init($0) },
             platforms: try input.package.platforms.map { try Self.parsePlatforms($0) } ?? [],
             targets: try input.package.targets.map { try Self.parseTarget(target: $0, identityResolver: identityResolver) },
             pkgConfig: input.package.pkgConfig,

Sources/PackageLoading/PackageBuilder.swift

@@ -1086,6 +1086,31 @@ public final class PackageBuilder {
         }
     }
 
+    private func resolvedSettings(for target: TargetDescription) -> [TargetBuildSettingDescription.Setting] {
+        var resolved = target.settings
+
+        let defaultSettings = manifest.defaultSettings ?? []
+
+        for defaultSetting in defaultSettings {
+            var eligible = true
+
+            // Look for an existing target setting that takes precedence. If none are found,
+            // the default is accepted.
+            for setting in resolved {
+                if setting.overridesDefault(defaultSetting) {
+                    eligible = false
+                    break
+                }
+            }
+
+            if eligible {
+                resolved.append(defaultSetting)
+            }
+        }
+
+        return resolved
+    }
+
     /// Creates build setting assignment table for the given target.
     func buildSettings(
         for target: TargetDescription?,
@@ -1103,7 +1128,7 @@ public final class PackageBuilder {
         table.add(versionAssignment, for: .SWIFT_VERSION)
 
         // Process each setting.
-        for setting in target.settings {
+        for setting in resolvedSettings(for: target) {
             if let traits = setting.condition?.traits, traits.intersection(self.enabledTraits.names).isEmpty {
                 // The setting is currently not enabled so we should skip it
                 continue

Sources/PackageModel/Manifest/Manifest.swift

@@ -74,6 +74,8 @@ public final class Manifest: Sendable {
     /// The declared package dependencies.
     public let dependencies: [PackageDependency]
 
+    public let defaultSwiftSettings: [TargetBuildSettingDescription.Setting]?
+
     /// The targets declared in the manifest.
     public let targets: [TargetDescription]
 
@@ -116,6 +118,7 @@ public final class Manifest: Sendable {
         packageKind: PackageReference.Kind,
         packageLocation: String,
         defaultLocalization: String?,
+        defaultSwiftSettings: [TargetBuildSettingDescription.Setting] = [],
         platforms: [PlatformDescription],
         version: TSCUtility.Version?,
         revision: String?,
@@ -137,6 +140,7 @@ public final class Manifest: Sendable {
         self.packageKind = packageKind
         self.packageLocation = packageLocation
         self.defaultLocalization = defaultLocalization
+        self.defaultSwiftSettings = defaultSwiftSettings
         self.platforms = platforms
         self.version = version
         self.revision = revision
@@ -610,6 +614,10 @@ public final class Manifest: Sendable {
         }
         return self.targetsWithCommonSourceRoot(type: type).count == 1
     }
+
+    public var defaultSettings: [TargetBuildSettingDescription.Setting] {
+        defaultSwiftSettings ?? []
+    }
 }
 
 extension Manifest: Hashable {
@@ -633,7 +641,7 @@ extension Manifest: Encodable {
         case name, path, url, version, targetMap, toolsVersion,
              pkgConfig, providers, cLanguageStandard, cxxLanguageStandard, swiftLanguageVersions,
              dependencies, products, targets, traits, platforms, packageKind, revision,
-             defaultLocalization
+             defaultLocalization, defaultSwiftSettings
     }
 
     /// Coding user info key for dump-package command.
@@ -656,6 +664,7 @@ extension Manifest: Encodable {
 
         try container.encode(self.toolsVersion, forKey: .toolsVersion)
         try container.encode(self.defaultLocalization, forKey: .defaultLocalization)
+        try container.encode(self.defaultSwiftSettings, forKey: .defaultSwiftSettings)
         try container.encode(self.pkgConfig, forKey: .pkgConfig)
         try container.encode(self.providers, forKey: .providers)
         try container.encode(self.cLanguageStandard, forKey: .cLanguageStandard)

Sources/PackageModel/Manifest/TargetBuildSettingDescription.swift

@@ -93,5 +93,34 @@ public enum TargetBuildSettingDescription {
             self.kind = kind
             self.condition = condition
         }
+
+        public func overridesDefault(_ defaultSetting: Setting) -> Bool {
+            guard tool == defaultSetting.tool else {
+                return false
+            }
+
+            switch (kind, defaultSetting.kind) {
+            case (.defaultIsolation, .defaultIsolation):
+                return true
+            case (.interoperabilityMode, .interoperabilityMode):
+                return true
+            case (.swiftLanguageMode, .swiftLanguageMode):
+                return true
+            case (.treatAllWarnings, .treatAllWarnings):
+                return true
+            case (.unsafeFlags, .unsafeFlags):
+                return true
+            case (.define, .define):
+                return true
+            case (.treatWarning(let value, _), .treatWarning(let defaultValue, _)):
+                return value == defaultValue
+            case (.enableWarning(let value), .disableWarning(let defaultValue)):
+                return value == defaultValue
+            case (.disableWarning(let value), .enableWarning(let defaultValue)):
+                return value == defaultValue
+            default:
+                return false
+            }
+        }
     }
 }

Sources/Runtimes/PackageDescription/PackageDescription.swift

@@ -114,6 +114,19 @@ public final class Package {
         set { swiftLanguageModes = newValue }
     }
 
+    /// The default Swift language settings merged with all per-target settings.
+    @available(_PackageDescription, introduced: 6.5)
+    public var defaultSwiftSettings: [SwiftSetting]?
+
+    @available(_PackageDescription, introduced: 6.5)
+    public var defaultCSettings: [CSetting]?
+
+    @available(_PackageDescription, introduced: 6.5)
+    public var defaultCXXSettings: [CXXSetting]?
+
+    @available(_PackageDescription, introduced: 6.5)
+    public var defaultLinkerSettings: [LinkerSetting]?
+
     /// The C language standard to use for all C targets in this package.
     public var cLanguageStandard: CLanguageStandard?
 
@@ -315,8 +328,12 @@ public final class Package {
         dependencies: [Dependency] = [],
         targets: [Target] = [],
         swiftLanguageModes: [SwiftLanguageMode]? = nil,
+        defaultSwiftSettings: [SwiftSetting]? = nil,
         cLanguageStandard: CLanguageStandard? = nil,
-        cxxLanguageStandard: CXXLanguageStandard? = nil
+        defaultCSettings: [CSetting]? = nil,
+        cxxLanguageStandard: CXXLanguageStandard? = nil,
+        defaultCXXSettings: [CXXSetting]? = nil,
+        defaultLinkerSettings: [LinkerSetting]? = nil
     ) {
         self.name = name
         self.defaultLocalization = defaultLocalization
@@ -328,8 +345,12 @@ public final class Package {
         self.targets = targets
         self.traits = []
         self.swiftLanguageModes = swiftLanguageModes
+        self.defaultSwiftSettings = defaultSwiftSettings
         self.cLanguageStandard = cLanguageStandard
+        self.defaultCSettings = defaultCSettings
         self.cxxLanguageStandard = cxxLanguageStandard
+        self.defaultCXXSettings = defaultCXXSettings
+        self.defaultLinkerSettings = defaultLinkerSettings
         registerExitHandler()
     }
 
@@ -362,8 +383,12 @@ public final class Package {
         dependencies: [Dependency] = [],
         targets: [Target] = [],
         swiftLanguageModes: [SwiftLanguageMode]? = nil,
+        defaultSwiftSettings: [SwiftSetting]? = nil,
         cLanguageStandard: CLanguageStandard? = nil,
-        cxxLanguageStandard: CXXLanguageStandard? = nil
+        defaultCSettings: [CSetting]? = nil,
+        cxxLanguageStandard: CXXLanguageStandard? = nil,
+        defaultCXXSettings: [CXXSetting]? = nil,
+        defaultLinkerSettings: [LinkerSetting]? = nil
     ) {
         self.name = name
         self.defaultLocalization = defaultLocalization
@@ -375,8 +400,12 @@ public final class Package {
         self.dependencies = dependencies
         self.targets = targets
         self.swiftLanguageModes = swiftLanguageModes
+        self.defaultSwiftSettings = defaultSwiftSettings
         self.cLanguageStandard = cLanguageStandard
+        self.defaultCSettings = defaultCSettings
         self.cxxLanguageStandard = cxxLanguageStandard
+        self.defaultCXXSettings = defaultCXXSettings
+        self.defaultLinkerSettings = defaultLinkerSettings
         registerExitHandler()
     }
 

Sources/Runtimes/PackageDescription/PackageDescriptionSerialization.swift

@@ -294,6 +294,10 @@ enum Serialization {
         let name: String
         let platforms: [SupportedPlatform]?
         let defaultLocalization: LanguageTag?
+        let defaultSwiftSettings: [SwiftSetting]?
+        let defaultCSettings: [CSetting]?
+        let defaultCXXSettings: [CXXSetting]?
+        let defaultLinkerSettings: [LinkerSetting]?
         let pkgConfig: String?
         let providers: [SystemPackageProvider]?
         let targets: [Target]

Sources/Runtimes/PackageDescription/PackageDescriptionSerializationConversion.swift

@@ -401,6 +401,10 @@ extension Serialization.Package {
         self.name = package.name
         self.platforms = package.platforms?.map { .init($0) }
         self.defaultLocalization = package.defaultLocalization.map { .init($0) }
+        self.defaultSwiftSettings = package.defaultSwiftSettings?.map { .init($0) }
+        self.defaultCSettings = package.defaultCSettings?.map { .init($0) }
+        self.defaultCXXSettings = package.defaultCXXSettings?.map { .init($0) }
+        self.defaultLinkerSettings = package.defaultLinkerSettings?.map { .init($0) }
         self.pkgConfig = package.pkgConfig
         self.providers = package.providers?.map { .init($0) }
         self.targets = package.targets.map { .init($0) }

Sources/_InternalTestSupport/ManifestExtensions.swift

@@ -21,6 +21,7 @@ extension Manifest {
         displayName: String,
         path: AbsolutePath = .root,
         defaultLocalization: String? = nil,
+        defaultSettings: [TargetBuildSettingDescription.Setting] = [],
         platforms: [PlatformDescription] = [],
         version: TSCUtility.Version? = nil,
         toolsVersion: ToolsVersion = .v4,
@@ -42,6 +43,7 @@ extension Manifest {
             packageIdentity: .plain(displayName.lowercased()),
             packageLocation: path.pathString,
             defaultLocalization: defaultLocalization,
+            defaultSettings: defaultSettings,
             platforms: platforms,
             version: version,
             toolsVersion: toolsVersion,
@@ -226,6 +228,7 @@ extension Manifest {
         packageIdentity: PackageIdentity,
         packageLocation: String? = nil,
         defaultLocalization: String? = nil,
+        defaultSettings: [TargetBuildSettingDescription.Setting] = [],
         platforms: [PlatformDescription] = [],
         version: TSCUtility.Version? = nil,
         toolsVersion: ToolsVersion,
@@ -247,6 +250,7 @@ extension Manifest {
             packageKind: packageKind,
             packageLocation: packageLocation ?? path.pathString,
             defaultLocalization: defaultLocalization,
+            defaultSwiftSettings: defaultSettings,
             platforms: platforms,
             version: version,
             revision: .none,