Generate entrypoints for test bundles on macOS (#9018)

Closes #8973

Ensure test bundles get a main symbol on macOS so swiftpm-testing-helper
can kick off tests. We may want to rename this entrypoint to solve some
issues with testable executables though.

Author: owenv

Sources/SwiftBuildSupport/PackagePIFProjectBuilder+Products.swift

@@ -430,7 +430,8 @@ extension PackagePIFProjectBuilder {
                             on: moduleDependencyGUID,
                             platformFilters: packageConditions
                                 .toPlatformFilter(toolsVersion: package.manifest.toolsVersion),
-                            linkProduct: true
+                            // Only link the testable version of executables which use Swift, as we do not currently support renaming entrypoints written in other languages.
+                            linkProduct: moduleDependency.usesSwift
                         )
                         log(.debug, indent: 1, "Added linked dependency on target '\(moduleDependencyGUID)'")
                     }

Sources/SwiftBuildSupport/SwiftBuildSystem.swift

@@ -413,7 +413,7 @@ public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
                         throw error
                     }
 
-                    let request = try self.makeBuildRequest(configuredTargets: configuredTargets, derivedDataPath: derivedDataPath, genSymbolGraph: genSymbolGraph)
+                    let request = try await self.makeBuildRequest(session: session, configuredTargets: configuredTargets, derivedDataPath: derivedDataPath, genSymbolGraph: genSymbolGraph)
 
                     struct BuildState {
                         private var targetsByID: [Int: SwiftBuild.SwiftBuildMessage.TargetStartedInfo] = [:]
@@ -521,7 +521,7 @@ public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
                         case .taskComplete(let info):
                             let startedInfo = try buildState.completed(task: info)
                             if info.result != .success {
-                                self.observabilityScope.emit(severity: .error, message: "\(startedInfo.ruleInfo) failed with a nonzero exit code")
+                                self.observabilityScope.emit(severity: .error, message: "\(startedInfo.ruleInfo) failed with a nonzero exit code. Command line: \(startedInfo.commandLineDisplayString ?? "<no command line>")")
                             }
                             let targetInfo = try buildState.target(for: startedInfo)
                             self.delegate?.buildSystem(self, didFinishCommand: BuildSystemCommand(startedInfo, targetInfo: targetInfo))
@@ -631,7 +631,7 @@ public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
         )
     }
 
-    private func makeBuildParameters(genSymbolGraph: Bool) throws -> SwiftBuild.SWBBuildParameters {
+    private func makeBuildParameters(session: SWBBuildServiceSession, genSymbolGraph: Bool) async throws -> SwiftBuild.SWBBuildParameters {
         // Generate the run destination parameters.
         let runDestination = makeRunDestination()
 
@@ -642,11 +642,20 @@ public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
 
         // Generate a table of any overriding build settings.
         var settings: [String: String] = [:]
-        // An error with determining the override should not be fatal here.
-        settings["CC"] = try? buildParameters.toolchain.getClangCompiler().pathString
-        // Always specify the path of the effective Swift compiler, which was determined in the same way as for the
-        // native build system.
-        settings["SWIFT_EXEC"] = buildParameters.toolchain.swiftCompilerPath.pathString
+
+        // If the SwiftPM toolchain corresponds to a toolchain registered with the lower level build system, add it to the toolchain stack.
+        // Otherwise, apply overrides for each component of the SwiftPM toolchain.
+        if let toolchainID = try await session.lookupToolchain(at: buildParameters.toolchain.toolchainDir.pathString) {
+            settings["TOOLCHAINS"] = "\(toolchainID.rawValue) $(inherited)"
+        } else {
+            // FIXME: This list of overrides is incomplete.
+            // An error with determining the override should not be fatal here.
+            settings["CC"] = try? buildParameters.toolchain.getClangCompiler().pathString
+            // Always specify the path of the effective Swift compiler, which was determined in the same way as for the
+            // native build system.
+            settings["SWIFT_EXEC"] = buildParameters.toolchain.swiftCompilerPath.pathString
+        }
+
         // FIXME: workaround for old Xcode installations such as what is in CI
         settings["LM_SKIP_METADATA_EXTRACTION"] = "YES"
         if genSymbolGraph {
@@ -705,6 +714,11 @@ public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
             settings["ARCHS"] = architectures.joined(separator: " ")
         }
 
+        // When building with the CLI for macOS, test bundles should generate entrypoints for compatibility with swiftpm-testing-helper.
+        if buildParameters.triple.isMacOSX {
+            settings["GENERATE_TEST_ENTRYPOINTS_FOR_BUNDLES"] = "YES"
+        }
+
         func reportConflict(_ a: String, _ b: String) throws -> String {
             throw StringError("Build parameters constructed conflicting settings overrides '\(a)' and '\(b)'")
         }
@@ -727,9 +741,9 @@ public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
         return params
     }
 
-    public func makeBuildRequest(configuredTargets: [SWBTargetGUID], derivedDataPath: Basics.AbsolutePath, genSymbolGraph: Bool) throws -> SWBBuildRequest {
+    public func makeBuildRequest(session: SWBBuildServiceSession, configuredTargets: [SWBTargetGUID], derivedDataPath: Basics.AbsolutePath, genSymbolGraph: Bool) async throws -> SWBBuildRequest {
         var request = SWBBuildRequest()
-        request.parameters = try makeBuildParameters(genSymbolGraph: genSymbolGraph)
+        request.parameters = try await makeBuildParameters(session: session, genSymbolGraph: genSymbolGraph)
         request.configuredTargets = configuredTargets.map { SWBConfiguredTarget(guid: $0.rawValue, parameters: request.parameters) }
         request.useParallelTargets = true
         request.useImplicitDependencies = false

Tests/CommandsTests/TestCommandTests.swift

@@ -221,7 +221,6 @@ struct TestCommandTests {
     }
 
     @Test(
-        .issue("https://github.com/swiftlang/swift-package-manager/issues/8955", relationship: .defect),
         arguments: SupportedBuildSystemOnAllPlatforms, BuildConfiguration.allCases,
     )
     func enableDisableTestabilityDefaultShouldRunWithTestability(
@@ -274,7 +273,7 @@ struct TestCommandTests {
                 }
 
                 #expect(
-                    stderr.contains("was not compiled for testing"),
+                    stderr.contains("was not compiled for testing") || stderr.contains("ignore swiftmodule built without '-enable-testing'"),
                     "got stdout: \(stdout), stderr: \(stderr)",
                 )
             }
@@ -668,7 +667,6 @@ struct TestCommandTests {
         } when: {
             (buildSystem == .swiftbuild && .linux == ProcessInfo.hostOperatingSystem)
                 || ProcessInfo.hostOperatingSystem == .windows
-                || (buildSystem == .swiftbuild && .macOS == ProcessInfo.hostOperatingSystem && tcdata.testRunner == .SwiftTesting)
         }
     }
 
@@ -995,8 +993,6 @@ struct TestCommandTests {
     }
 
     @Test(
-        .SWBINTTODO("Fails to find test executable"),
-        .issue("https://github.com/swiftlang/swift-package-manager/pull/8722", relationship: .fixedBy),
         arguments: SupportedBuildSystemOnAllPlatforms, BuildConfiguration.allCases,
     )
     func basicSwiftTestingIntegration(
@@ -1017,7 +1013,7 @@ struct TestCommandTests {
                 )
             }
         } when: {
-            buildSystem == .swiftbuild
+            buildSystem == .swiftbuild && ProcessInfo.hostOperatingSystem != .macOS
         }
     }