Make Resolved* in PackageGraph value types

Sources/Build/BuildDescription/ClangTargetBuildDescription.swift

@@ -13,7 +13,7 @@
 import Basics
 import PackageLoading
 import PackageModel
-import class PackageGraph.ResolvedTarget
+import struct PackageGraph.ResolvedTarget
 import struct SPMBuildCore.BuildParameters
 import struct SPMBuildCore.BuildToolPluginInvocationResult
 import struct SPMBuildCore.PrebuildCommandResult
@@ -26,9 +26,7 @@ public final class ClangTargetBuildDescription {
     public let target: ResolvedTarget
 
     /// The underlying clang target.
-    public var clangTarget: ClangTarget {
-        target.underlyingTarget as! ClangTarget
-    }
+    public let clangTarget: ClangTarget
 
     /// The tools version of the package that declared the target.  This can
     /// can be used to conditionalize semantically significant changes in how
@@ -45,7 +43,7 @@ public final class ClangTargetBuildDescription {
 
     /// The list of all resource files in the target, including the derived ones.
     public var resources: [Resource] {
-        self.target.underlyingTarget.resources + self.pluginDerivedResources
+        self.target.underlying.resources + self.pluginDerivedResources
     }
 
     /// Path to the bundle generated for this module (if any).
@@ -54,7 +52,7 @@ public final class ClangTargetBuildDescription {
             return .none
         }
 
-        if let bundleName = target.underlyingTarget.potentialBundleName {
+        if let bundleName = target.underlying.potentialBundleName {
             return self.buildParameters.bundlePath(named: bundleName)
         } else {
             return .none
@@ -119,10 +117,11 @@ public final class ClangTargetBuildDescription {
         fileSystem: FileSystem,
         observabilityScope: ObservabilityScope
     ) throws {
-        guard target.underlyingTarget is ClangTarget else {
+        guard let clangTarget = target.underlying as? ClangTarget else {
             throw InternalError("underlying target type mismatch \(target)")
         }
 
+        self.clangTarget = clangTarget
         self.fileSystem = fileSystem
         self.target = target
         self.toolsVersion = toolsVersion

Sources/Build/BuildDescription/PluginDescription.swift

@@ -50,7 +50,7 @@ public final class PluginDescription: Codable {
         testDiscoveryTarget: Bool = false,
         fileSystem: FileSystem
     ) throws {
-        guard target.underlyingTarget is PluginTarget else {
+        guard target.underlying is PluginTarget else {
             throw InternalError("underlying target type mismatch \(target)")
         }
 

Sources/Build/BuildDescription/ProductBuildDescription.swift

@@ -236,7 +236,7 @@ public final class ProductBuildDescription: SPMBuildCore.ProductBuildDescription
             // Support for linking tests against executables is conditional on the tools
             // version of the package that defines the executable product.
             let executableTarget = try product.executableTarget
-            if let target = executableTarget.underlyingTarget as? SwiftTarget, 
+            if let target = executableTarget.underlying as? SwiftTarget, 
                 self.toolsVersion >= .v5_5,
                 self.buildParameters.driverParameters.canRenameEntrypointFunctionName,
                 target.supportsTestableExecutablesFeature

Sources/Build/BuildDescription/SharedTargetBuildDescription.swift

@@ -53,7 +53,7 @@ struct SharedTargetBuildDescription {
             additionalFileRules: additionalFileRules,
             defaultLocalization: target.defaultLocalization,
             targetName: target.name,
-            targetPath: target.underlyingTarget.path,
+            targetPath: target.underlying.path,
             observabilityScope: observabilityScope
         )
         let pluginDerivedResources = derivedResources

Sources/Build/BuildDescription/SwiftTargetBuildDescription.swift

@@ -33,6 +33,8 @@ public final class SwiftTargetBuildDescription {
     /// The target described by this target.
     public let target: ResolvedTarget
 
+    private let swiftTarget: SwiftTarget
+
     /// The tools version of the package that declared the target.  This can
     /// can be used to conditionalize semantically significant changes in how
     /// a target is built.
@@ -57,7 +59,7 @@ public final class SwiftTargetBuildDescription {
 
     /// Path to the bundle generated for this module (if any).
     var bundlePath: AbsolutePath? {
-        if let bundleName = target.underlyingTarget.potentialBundleName, needsResourceBundle {
+        if let bundleName = target.underlying.potentialBundleName, needsResourceBundle {
             return self.buildParameters.bundlePath(named: bundleName)
         } else {
             return .none
@@ -83,7 +85,7 @@ public final class SwiftTargetBuildDescription {
 
     /// The list of all resource files in the target, including the derived ones.
     public var resources: [Resource] {
-        self.target.underlyingTarget.resources + self.pluginDerivedResources
+        self.target.underlying.resources + self.pluginDerivedResources
     }
 
     /// The objects in this target, containing either machine code or bitcode
@@ -139,7 +141,7 @@ public final class SwiftTargetBuildDescription {
 
     /// The swift version for this target.
     var swiftVersion: SwiftLanguageVersion {
-        (self.target.underlyingTarget as! SwiftTarget).swiftVersion
+        self.swiftTarget.swiftVersion
     }
 
     /// Describes the purpose of a test target, including any special roles such as containing a list of discovered
@@ -257,10 +259,11 @@ public final class SwiftTargetBuildDescription {
         fileSystem: FileSystem,
         observabilityScope: ObservabilityScope
     ) throws {
-        guard target.underlyingTarget is SwiftTarget else {
+        guard let swiftTarget = target.underlying as? SwiftTarget else {
             throw InternalError("underlying target type mismatch \(target)")
         }
 
+        self.swiftTarget = swiftTarget
         self.package = package
         self.target = target
         self.toolsVersion = toolsVersion
@@ -514,7 +517,7 @@ public final class SwiftTargetBuildDescription {
         // when we link the executable, we will ask the linker to rename the entry point
         // symbol to just `_main` again (or if the linker doesn't support it, we'll
         // generate a source containing a redirect).
-        if (self.target.underlyingTarget as? SwiftTarget)?.supportsTestableExecutablesFeature == true
+        if (self.target.underlying as? SwiftTarget)?.supportsTestableExecutablesFeature == true
             && !self.isTestTarget && self.toolsVersion >= .v5_5
         {
             // We only do this if the linker supports it, as indicated by whether we

Sources/Build/BuildDescription/TargetBuildDescription.swift

@@ -11,10 +11,10 @@
 //===----------------------------------------------------------------------===//
 
 import Basics
-import struct SPMBuildCore.BuildParameters
-import class PackageGraph.ResolvedTarget
+import struct PackageGraph.ResolvedTarget
 import struct PackageModel.Resource
 import struct SPMBuildCore.BuildToolPluginInvocationResult
+import struct SPMBuildCore.BuildParameters
 
 public enum BuildDescriptionError: Swift.Error {
     case requestedFileNotPartOfTarget(targetName: String, requestedFilePath: AbsolutePath)

Sources/Build/BuildManifest/LLBuildManifestBuilder+Clang.swift

@@ -13,7 +13,7 @@
 import struct LLBuildManifest.Node
 import struct Basics.AbsolutePath
 import struct Basics.InternalError
-import class PackageGraph.ResolvedTarget
+import struct PackageGraph.ResolvedTarget
 import PackageModel
 
 extension LLBuildManifestBuilder {

Sources/Build/BuildManifest/LLBuildManifestBuilder+Swift.swift

@@ -17,7 +17,7 @@ import struct Basics.TSCAbsolutePath
 import struct LLBuildManifest.Node
 import struct LLBuildManifest.LLBuildManifest
 import struct SPMBuildCore.BuildParameters
-import class PackageGraph.ResolvedTarget
+import struct PackageGraph.ResolvedTarget
 import protocol TSCBasic.FileSystem
 import enum TSCBasic.ProcessEnv
 import func TSCBasic.topologicalSort
@@ -212,8 +212,8 @@ extension LLBuildManifestBuilder {
                 // product into its constituent targets.
                 continue
             }
-            guard target.underlyingTarget.type != .systemModule,
-                  target.underlyingTarget.type != .binary
+            guard target.underlying.type != .systemModule,
+                  target.underlying.type != .binary
             else {
                 // Much like non-Swift targets, system modules will consist of a modulemap
                 // somewhere in the filesystem, with the path to that module being either
@@ -416,11 +416,11 @@ extension LLBuildManifestBuilder {
 
         func addStaticTargetInputs(_ target: ResolvedTarget) throws {
             // Ignore C Modules.
-            if target.underlyingTarget is SystemLibraryTarget { return }
+            if target.underlying is SystemLibraryTarget { return }
             // Ignore Binary Modules.
-            if target.underlyingTarget is BinaryTarget { return }
+            if target.underlying is BinaryTarget { return }
             // Ignore Plugin Targets.
-            if target.underlyingTarget is PluginTarget { return }
+            if target.underlying is PluginTarget { return }
 
             // Depend on the binary for executable targets.
             if target.type == .executable {

Sources/Build/BuildOperation.swift

@@ -511,7 +511,7 @@ public final class BuildOperation: PackageStructureDelegate, SPMBuildCore.BuildS
         for package in graph.rootPackages where package.manifest.toolsVersion >= .v5_3 {
             for target in package.targets {
                 // Get the set of unhandled files in targets.
-                var unhandledFiles = Set(target.underlyingTarget.others)
+                var unhandledFiles = Set(target.underlying.others)
                 if unhandledFiles.isEmpty { continue }
 
                 // Subtract out any that were inputs to any commands generated by plugins.

Sources/Build/BuildPlan/BuildPlan+Clang.swift

@@ -21,7 +21,7 @@ extension BuildPlan {
         let dependencies = try clangTarget.target.recursiveDependencies(satisfying: clangTarget.buildEnvironment)
 
         for case .target(let dependency, _) in dependencies {
-            switch dependency.underlyingTarget {
+            switch dependency.underlying {
             case is SwiftTarget:
                 if case let .swift(dependencyTargetDescription)? = targetMap[dependency] {
                     if let moduleMap = dependencyTargetDescription.moduleMap {

Sources/Build/BuildPlan/BuildPlan+Product.swift

@@ -13,8 +13,8 @@
 import struct Basics.AbsolutePath
 import struct Basics.Triple
 import struct Basics.InternalError
-import class PackageGraph.ResolvedProduct
-import class PackageGraph.ResolvedTarget
+import struct PackageGraph.ResolvedProduct
+import struct PackageGraph.ResolvedTarget
 import class PackageModel.BinaryTarget
 import class PackageModel.ClangTarget
 import class PackageModel.Target
@@ -32,7 +32,7 @@ extension BuildPlan {
 
         // Add flags for system targets.
         for systemModule in dependencies.systemModules {
-            guard case let target as SystemLibraryTarget = systemModule.underlyingTarget else {
+            guard case let target as SystemLibraryTarget = systemModule.underlying else {
                 throw InternalError("This should not be possible.")
             }
             // Add pkgConfig libs arguments.
@@ -53,7 +53,7 @@ extension BuildPlan {
         // Link C++ if needed.
         // Note: This will come from build settings in future.
         for target in dependencies.staticTargets {
-            if case let target as ClangTarget = target.underlyingTarget, target.isCXX {
+            if case let target as ClangTarget = target.underlying, target.isCXX {
                 let triple = buildProduct.buildParameters.triple
                 if triple.isDarwin() {
                     buildProduct.additionalFlags += ["-lc++"]
@@ -67,7 +67,7 @@ extension BuildPlan {
         }
 
         for target in dependencies.staticTargets {
-            switch target.underlyingTarget {
+            switch target.underlying {
             case is SwiftTarget:
                 // Swift targets are guaranteed to have a corresponding Swift description.
                 guard case .swift(let description) = targetMap[target] else {
@@ -131,7 +131,7 @@ extension BuildPlan {
         // For test targets, we need to consider the first level of transitive dependencies since the first level is always test targets.
         let topLevelDependencies: [PackageModel.Target]
         if product.type == .test {
-            topLevelDependencies = product.targets.flatMap { $0.underlyingTarget.dependencies }.compactMap {
+            topLevelDependencies = product.targets.flatMap { $0.underlying.dependencies }.compactMap {
                 switch $0 {
                 case .product:
                     return nil
@@ -149,7 +149,7 @@ extension BuildPlan {
             switch dependency {
             // Include all the dependencies of a target.
             case .target(let target, _):
-                let isTopLevel = topLevelDependencies.contains(target.underlyingTarget) || product.targets.contains(target)
+                let isTopLevel = topLevelDependencies.contains(target.underlying) || product.targets.contains(target)
                 let topLevelIsMacro = isTopLevel && product.type == .macro
                 let topLevelIsPlugin = isTopLevel && product.type == .plugin
                 let topLevelIsTest = isTopLevel && product.type == .test
@@ -200,9 +200,9 @@ extension BuildPlan {
                 case .executable, .snippet, .macro:
                     if product.targets.contains(target) {
                         staticTargets.append(target)
-                    } else if product.type == .test && (target.underlyingTarget as? SwiftTarget)?.supportsTestableExecutablesFeature == true {
+                    } else if product.type == .test && (target.underlying as? SwiftTarget)?.supportsTestableExecutablesFeature == true {
                         // Only "top-level" targets should really be considered here, not transitive ones.
-                        let isTopLevel = topLevelDependencies.contains(target.underlyingTarget) || product.targets.contains(target)
+                        let isTopLevel = topLevelDependencies.contains(target.underlying) || product.targets.contains(target)
                         if let toolsVersion = graph.package(for: product)?.manifest.toolsVersion, toolsVersion >= .v5_5, isTopLevel {
                             staticTargets.append(target)
                         }
@@ -220,7 +220,7 @@ extension BuildPlan {
                     systemModules.append(target)
                 // Add binary to binary paths set.
                 case .binary:
-                    guard let binaryTarget = target.underlyingTarget as? BinaryTarget else {
+                    guard let binaryTarget = target.underlying as? BinaryTarget else {
                         throw InternalError("invalid binary target '\(target.name)'")
                     }
                     switch binaryTarget.kind {

Sources/Build/BuildPlan/BuildPlan+Swift.swift

@@ -21,7 +21,7 @@ extension BuildPlan {
         // depends on.
         let environment = swiftTarget.buildParameters.buildEnvironment
         for case .target(let dependency, _) in try swiftTarget.target.recursiveDependencies(satisfying: environment) {
-            switch dependency.underlyingTarget {
+            switch dependency.underlying {
             case let underlyingTarget as ClangTarget where underlyingTarget.type == .library:
                 guard case let .clang(target)? = targetMap[dependency] else {
                     throw InternalError("unexpected clang target \(underlyingTarget)")