Merge pull request #903 from nkcsgexi/use-warning-interface-verify

Pass-down -downgrade-typecheck-interface-error to interface verification job

Author: nkcsgexi

Sources/SwiftDriver/Jobs/Planning.swift

@@ -452,6 +452,8 @@ extension Driver {
                               default: false)
     else { return }
 
+    let optIn = env["ENABLE_DEFAULT_INTERFACE_VERIFIER"] != nil ||
+      parsedOptions.hasArgument(.verifyEmittedModuleInterface)
     func addVerifyJob(forPrivate: Bool) throws {
       let isNeeded =
         forPrivate
@@ -464,11 +466,11 @@ extension Driver {
       let mergeInterfaceOutputs = emitModuleJob.outputs.filter { $0.type == outputType }
       assert(mergeInterfaceOutputs.count == 1,
              "Merge module job should only have one swiftinterface output")
-      let job = try verifyModuleInterfaceJob(interfaceInput: mergeInterfaceOutputs[0])
+      let job = try verifyModuleInterfaceJob(interfaceInput: mergeInterfaceOutputs[0], optIn: optIn)
       addJob(job)
     }
     try addVerifyJob(forPrivate: false)
-    try addVerifyJob(forPrivate: true )
+    try addVerifyJob(forPrivate: true)
   }
 
   private mutating func addAutolinkExtractJob(

Sources/SwiftDriver/Jobs/VerifyModuleInterfaceJob.swift

@@ -11,7 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 extension Driver {
-  mutating func verifyModuleInterfaceJob(interfaceInput: TypedVirtualPath) throws -> Job {
+  mutating func verifyModuleInterfaceJob(interfaceInput: TypedVirtualPath, optIn: Bool) throws -> Job {
     var commandLine: [Job.ArgTemplate] = swiftCompilerPrefixArgs.map { Job.ArgTemplate.flag($0) }
     var inputs: [TypedVirtualPath] = [interfaceInput]
     commandLine.appendFlags("-frontend", "-typecheck-module-from-interface")
@@ -26,6 +26,10 @@ extension Driver {
       outputs.append(TypedVirtualPath(file: outputPath, type: .diagnostics))
     }
 
+    // TODO: remove this because we'd like module interface errors to fail the build.
+    if !optIn && isFrontendArgSupported(.downgradeTypecheckInterfaceError) {
+      commandLine.appendFlag(.downgradeTypecheckInterfaceError)
+    }
     return Job(
       moduleName: moduleOutputInfo.name,
       kind: .verifyModuleInterface,