Verify emitted modules interfaces of public frameworks by default

rdar://82987741

Author: xymus

Sources/SwiftDriver/Jobs/Planning.swift

@@ -430,11 +430,15 @@ extension Driver {
 
   private mutating func addVerifyJobs(emitModuleJob: Job, addJob: (Job) -> Void )
   throws {
+    // Turn this flag on by default with the env var or for public frameworks.
+    let onByDefault = env["ENABLE_DEFAULT_INTERFACE_VERIFIER"] != nil ||
+        parsedOptions.getLastArgument(.libraryLevel)?.asSingle == "api"
+
     guard
        parsedOptions.hasArgument(.enableLibraryEvolution),
        parsedOptions.hasFlag(positive: .verifyEmittedModuleInterface,
                              negative: .noVerifyEmittedModuleInterface,
-                             default: true),
+                             default: onByDefault),
 
       // Don't verify by default modules emitted from a merge-module job
       // as it's more likely to be invalid
@@ -444,12 +448,6 @@ extension Driver {
                               default: false)
     else { return }
 
-    // FIXME: remove this when we are confident to enable interface verification
-    // by default.
-    if env["ENABLE_DEFAULT_INTERFACE_VERIFIER"] == nil &&
-        !parsedOptions.hasArgument(.verifyEmittedModuleInterface) {
-      return
-    }
     func addVerifyJob(forPrivate: Bool) throws {
       let isNeeded =
         forPrivate

Tests/SwiftDriverTests/SwiftDriverTests.swift

@@ -4107,6 +4107,30 @@ final class SwiftDriverTests: XCTestCase {
       XCTAssertTrue(verifyJob.inputs[0] == emitInterfaceOutput[0])
       XCTAssertTrue(verifyJob.commandLine.contains(.path(emitInterfaceOutput[0].file)))
     }
+
+    // Enabled by default when the library-level is api.
+    do {
+      var driver = try Driver(args: ["swiftc", "foo.swift", "-emit-module", "-module-name",
+                                     "foo", "-emit-module-interface",
+                                     "-enable-library-evolution",
+                                     "-whole-module-optimization",
+                                     "-library-level", "api"])
+      let plannedJobs = try driver.planBuild()
+      XCTAssertEqual(plannedJobs.count, 2)
+      XCTAssertTrue(plannedJobs.contains() {$0.kind == .verifyModuleInterface})
+    }
+
+    // Not enabled by default when the library-level is spi.
+    do {
+      var driver = try Driver(args: ["swiftc", "foo.swift", "-emit-module", "-module-name",
+                                     "foo", "-emit-module-interface",
+                                     "-enable-library-evolution",
+                                     "-whole-module-optimization",
+                                     "-library-level", "spi"])
+      let plannedJobs = try driver.planBuild()
+      XCTAssertEqual(plannedJobs.count, 1)
+      XCTAssertEqual(plannedJobs[0].kind, .compile)
+    }
   }
 
   func testPCHGeneration() throws {