swiftinterface verification: disable verify for modules with generated headers

Swiftinterface verification is incompatible with modules using generated
headers. Let's disable verification automatically in such a case.

Author: xymus

Sources/SwiftDriver/Jobs/Planning.swift

@@ -445,17 +445,27 @@ extension Driver {
         parsedOptions.getLastArgument(.libraryLevel)?.asSingle == "api"
 
     guard
-       parsedOptions.hasArgument(.enableLibraryEvolution),
-       parsedOptions.hasFlag(positive: .verifyEmittedModuleInterface,
-                             negative: .noVerifyEmittedModuleInterface,
-                             default: onByDefault),
+      // Only verify modules with library evolution.
+      parsedOptions.hasArgument(.enableLibraryEvolution),
+
+      // Only verify when requested, on by default and not disabled.
+      parsedOptions.hasFlag(positive: .verifyEmittedModuleInterface,
+                            negative: .noVerifyEmittedModuleInterface,
+                            default: onByDefault),
 
       // Don't verify by default modules emitted from a merge-module job
       // as it's more likely to be invalid.
       emitModuleSeparately || compilerMode == .singleCompile ||
-        parsedOptions.hasFlag(positive: .verifyEmittedModuleInterface,
-                              negative: .noVerifyEmittedModuleInterface,
-                              default: false)
+      parsedOptions.hasFlag(positive: .verifyEmittedModuleInterface,
+                            negative: .noVerifyEmittedModuleInterface,
+                            default: false),
+
+      // Don't verify by default modules emitting a compatibility header. This is
+      // unsupported as the headers are merged after all archs are built. rdar://90864986
+      self.objcGeneratedHeaderPath == nil ||
+      parsedOptions.hasFlag(positive: .verifyEmittedModuleInterface,
+                            negative: .noVerifyEmittedModuleInterface,
+                            default: false)
     else { return }
 
     let optIn = env["ENABLE_DEFAULT_INTERFACE_VERIFIER"] != nil ||

Tests/SwiftDriverTests/SwiftDriverTests.swift

@@ -4985,6 +4985,16 @@ final class SwiftDriverTests: XCTestCase {
       let verifyJob = plannedJobs.first(where: { $0.kind == .verifyModuleInterface })!
       XCTAssertFalse(verifyJob.commandLine.contains(.flag("-check-api-availability-only")))
     }
+
+    // Don't verify modules with compatibility headers.
+    do {
+      var driver = try Driver(args: ["swiftc", "foo.swift", "-emit-module", "-module-name",
+                                     "foo", "-emit-module-interface",
+                                     "-enable-library-evolution", "-emit-objc-header-path", "foo-Swift.h"],
+                              env: envVars)
+      let plannedJobs = try driver.planBuild()
+      XCTAssertEqual(plannedJobs.filter( { job in job.kind == .verifyModuleInterface}).count, 0)
+    }
   }
 
   func testPCHGeneration() throws {