Revert #7766 and #7783.

Sources/Build/BuildManifest/LLBuildManifestBuilder.swift

@@ -112,7 +112,9 @@ public class LLBuildManifestBuilder {
             }
         }
 
-        try self.addTestDiscoveryGenerationCommand()
+        if self.plan.destinationBuildParameters.testingParameters.library == .xctest {
+            try self.addTestDiscoveryGenerationCommand()
+        }
         try self.addTestEntryPointGenerationCommand()
 
         // Create command for all products in the plan.
@@ -308,7 +310,9 @@ extension LLBuildManifestBuilder {
 
             let outputs = testEntryPointTarget.target.sources.paths
 
-            let mainFileName = TestEntryPointTool.mainFileName
+            let mainFileName = TestEntryPointTool.mainFileName(
+                for: self.plan.destinationBuildParameters.testingParameters.library
+            )
             guard let mainOutput = (outputs.first { $0.basename == mainFileName }) else {
                 throw InternalError("main output (\(mainFileName)) not found")
             }

Sources/Build/BuildPlan/BuildPlan+Product.swift

@@ -275,8 +275,10 @@ extension BuildPlan {
         }
 
         // Add derived test targets, if necessary
-        if product.type == .test, let derivedTestTargets = derivedTestTargetsMap[product.id] {
-            staticTargets.append(contentsOf: derivedTestTargets)
+        if buildParameters.testingParameters.testProductStyle.requiresAdditionalDerivedTestTargets {
+            if product.type == .test, let derivedTestTargets = derivedTestTargetsMap[product.id] {
+                staticTargets.append(contentsOf: derivedTestTargets)
+            }
         }
 
         return (linkLibraries, staticTargets, systemModules, libraryBinaryPaths, providedLibraries, availableTools)

Sources/Build/BuildPlan/BuildPlan+Test.swift

@@ -34,12 +34,13 @@ extension BuildPlan {
         _ fileSystem: FileSystem,
         _ observabilityScope: ObservabilityScope
     ) throws -> [(product: ResolvedProduct, discoveryTargetBuildDescription: SwiftModuleBuildDescription?, entryPointTargetBuildDescription: SwiftModuleBuildDescription)] {
-        var explicitlyEnabledDiscovery = false
-        var explicitlySpecifiedPath: AbsolutePath?
-        if case let .entryPointExecutable(caseExplicitlyEnabledDiscovery, caseExplicitlySpecifiedPath) = destinationBuildParameters.testingParameters.testProductStyle {
-            explicitlyEnabledDiscovery = caseExplicitlyEnabledDiscovery
-            explicitlySpecifiedPath = caseExplicitlySpecifiedPath
+        guard destinationBuildParameters.testingParameters.testProductStyle.requiresAdditionalDerivedTestTargets,
+              case .entryPointExecutable(let explicitlyEnabledDiscovery, let explicitlySpecifiedPath) =
+                destinationBuildParameters.testingParameters.testProductStyle
+        else {
+            throw InternalError("makeTestManifestTargets should not be used for build plan which does not require additional derived test targets")
         }
+
         let isEntryPointPathSpecifiedExplicitly = explicitlySpecifiedPath != nil
 
         var isDiscoveryEnabledRedundantly = explicitlyEnabledDiscovery && !isEntryPointPathSpecifiedExplicitly
@@ -115,7 +116,7 @@ extension BuildPlan {
                 resolvedTargetDependencies: [ResolvedModule.Dependency]
             ) throws -> SwiftModuleBuildDescription {
                 let entryPointDerivedDir = destinationBuildParameters.buildPath.appending(components: "\(testProduct.name).derived")
-                let entryPointMainFileName = TestEntryPointTool.mainFileName
+                let entryPointMainFileName = TestEntryPointTool.mainFileName(for: destinationBuildParameters.testingParameters.library)
                 let entryPointMainFile = entryPointDerivedDir.appending(component: entryPointMainFileName)
                 let entryPointSources = Sources(paths: [entryPointMainFile], root: entryPointDerivedDir)
 
@@ -152,17 +153,18 @@ extension BuildPlan {
             let swiftTargetDependencies: [Module.Dependency]
             let resolvedTargetDependencies: [ResolvedModule.Dependency]
 
-            if destinationBuildParameters.triple.isDarwin() {
-                discoveryTargets = nil
-                swiftTargetDependencies = []
-                resolvedTargetDependencies = []
-            } else {
+            switch destinationBuildParameters.testingParameters.library {
+            case .xctest:
                 discoveryTargets = try generateDiscoveryTargets()
                 swiftTargetDependencies = [.module(discoveryTargets!.target, conditions: [])]
                 resolvedTargetDependencies = [.module(discoveryTargets!.resolved, conditions: [])]
+            case .swiftTesting:
+                discoveryTargets = nil
+                swiftTargetDependencies = testProduct.modules.map { .module($0.underlying, conditions: []) }
+                resolvedTargetDependencies = testProduct.modules.map { .module($0, conditions: []) }
             }
 
-            if !destinationBuildParameters.triple.isDarwin(), let entryPointResolvedTarget = testProduct.testEntryPointModule {
+            if let entryPointResolvedTarget = testProduct.testEntryPointModule {
                 if isEntryPointPathSpecifiedExplicitly || explicitlyEnabledDiscovery {
                     if isEntryPointPathSpecifiedExplicitly {
                         // Allow using the explicitly-specified test entry point target, but still perform test discovery and thus declare a dependency on the discovery modules.

Sources/Build/BuildPlan/BuildPlan.swift

@@ -473,29 +473,31 @@ public class BuildPlan: SPMBuildCore.BuildPlan {
         }
 
         // Plan the derived test targets, if necessary.
-        let derivedTestTargets = try Self.makeDerivedTestTargets(
-            testProducts: productMap.values.filter {
-                $0.product.type == .test
-            },
-            destinationBuildParameters: destinationBuildParameters,
-            toolsBuildParameters: toolsBuildParameters,
-            shouldDisableSandbox: self.shouldDisableSandbox,
-            self.fileSystem,
-            self.observabilityScope
-        )
-        for item in derivedTestTargets {
-            var derivedTestTargets = [item.entryPointTargetBuildDescription.target]
-
-            targetMap[item.entryPointTargetBuildDescription.target.id] = .swift(
-                item.entryPointTargetBuildDescription
+        if destinationBuildParameters.testingParameters.testProductStyle.requiresAdditionalDerivedTestTargets {
+            let derivedTestTargets = try Self.makeDerivedTestTargets(
+                testProducts: productMap.values.filter {
+                    $0.product.type == .test
+                },
+                destinationBuildParameters: destinationBuildParameters,
+                toolsBuildParameters: toolsBuildParameters,
+                shouldDisableSandbox: self.shouldDisableSandbox,
+                self.fileSystem,
+                self.observabilityScope
             )
+            for item in derivedTestTargets {
+                var derivedTestTargets = [item.entryPointTargetBuildDescription.target]
 
-            if let discoveryTargetBuildDescription = item.discoveryTargetBuildDescription {
-                targetMap[discoveryTargetBuildDescription.target.id] = .swift(discoveryTargetBuildDescription)
-                derivedTestTargets.append(discoveryTargetBuildDescription.target)
-            }
+                targetMap[item.entryPointTargetBuildDescription.target.id] = .swift(
+                    item.entryPointTargetBuildDescription
+                )
+
+                if let discoveryTargetBuildDescription = item.discoveryTargetBuildDescription {
+                    targetMap[discoveryTargetBuildDescription.target.id] = .swift(discoveryTargetBuildDescription)
+                    derivedTestTargets.append(discoveryTargetBuildDescription.target)
+                }
 
-            self.derivedTestTargetsMap[item.product.id] = derivedTestTargets
+                self.derivedTestTargetsMap[item.product.id] = derivedTestTargets
+            }
         }
 
         self.buildToolPluginInvocationResults = buildToolPluginInvocationResults