Pass -platform_version to the linker when prelinking a target on Darwin platforms

rdar://154346861

Author: owenv

Sources/SWBCore/SpecImplementations/Tools/PrelinkedObjectLink.swift

@@ -35,6 +35,13 @@ public final class PrelinkedObjectLinkSpec: CommandLineToolSpec, SpecImplementat
         var commandLine = [toolSpecInfo.toolPath.str]
         commandLine += ["-r", "-arch", arch]
 
+        if let buildPlatform = cbc.producer.sdk?.targetBuildVersionPlatform(sdkVariant: cbc.producer.sdkVariant),
+           let deploymentTargetMacro = cbc.producer.platform?.deploymentTargetMacro,
+           let minDeploymentTarget = cbc.scope.evaluate(deploymentTargetMacro).nilIfEmpty,
+           let sdkVersion = cbc.producer.sdk?.version {
+            commandLine += ["-platform_version", "\(buildPlatform.rawValue)", minDeploymentTarget, sdkVersion.canonicalDeploymentTargetForm.description]
+        }
+
         // We do not pass the deployment target to the linker here.  Instead the linker infers the platform and deployment target from the .o files being collected.  We did briefly pass it to the linker to silence a linker warning - if we ever see issues here we should confer with the linker folks to make sure we do the right thing.  See <rdar://problem/51800525> for more about the history here.
 
         let sysroot = cbc.scope.evaluate(BuiltinMacros.SDK_DIR)

Tests/SWBBuildSystemTests/LinkerTests.swift

@@ -360,4 +360,72 @@ fileprivate struct LinkerTests: CoreBasedTests {
             }
         }
     }
+
+    @Test(.requireSDKs(.macOS))
+    func prelinkingPropagatesPlatformVersion() async throws {
+        func createProject(_ tmpDir: Path, enableInterop: Bool) -> TestProject {
+            TestProject(
+                "TestProject",
+                sourceRoot: tmpDir,
+                groupTree: TestGroup(
+                    "SomeFiles",
+                    children: [
+                        TestFile("main.c"),
+                        TestFile("lib.c"),
+                    ]),
+                targets: [
+                    TestStandardTarget(
+                        "cli", type: .commandLineTool,
+                        buildConfigurations: [
+                            TestBuildConfiguration(
+                                "Debug",
+                                buildSettings: [
+                                    "PRODUCT_NAME": "$(TARGET_NAME)",
+                                    "CODE_SIGNING_ALLOWED": "NO",
+                                    "GENERATE_PRELINK_OBJECT_FILE": "YES",
+                                    "GCC_SYMBOLS_PRIVATE_EXTERN": "NO",
+                                    "MACOSX_DEPLOYMENT_TARGET": "13.0",
+                                ])
+                        ],
+                        buildPhases: [
+                            TestSourcesBuildPhase(["main.c"]),
+                            TestFrameworksBuildPhase([TestBuildFile(.target("lib"))])
+                        ],
+                        dependencies: [TestTargetDependency("lib")]
+                    ),
+                    TestStandardTarget(
+                        "lib", type: .staticLibrary,
+                        buildConfigurations: [
+                            TestBuildConfiguration(
+                                "Debug",
+                                buildSettings: [
+                                    "PRODUCT_NAME": "$(TARGET_NAME)",
+                                    "MACOSX_DEPLOYMENT_TARGET": "13.0",
+                                ])
+                        ],
+                        buildPhases: [
+                            TestSourcesBuildPhase(["lib.c"])
+                        ]
+                    ),
+                ])
+        }
+
+        try await withTemporaryDirectory { tmpDir in
+            let testProject = createProject(tmpDir, enableInterop: true)
+            let tester = try await BuildOperationTester(getCore(), testProject, simulated: false)
+            let projectDir = tester.workspace.projects[0].sourceRoot
+            try await tester.fs.writeFileContents(projectDir.join("main.c")) { stream in
+                stream <<< "int foo(void); int main(void) { foo(); }"
+            }
+            try await tester.fs.writeFileContents(projectDir.join("lib.c")) { stream in
+                stream <<< "int foo(void) { return 42; }"
+            }
+            try await tester.checkBuild(runDestination: .macOS) { results in
+                results.checkNoDiagnostics()
+                results.checkTask(.matchRuleType("PrelinkedObjectLink")) { task in
+                    task.checkCommandLineContainsUninterrupted(["-platform_version", "1", "13.0"])
+                }
+            }
+        }
+    }
 }