Invoke Explicit Interface Build when '-explicit-interface-module-build' is specified on a '-compile-module-from-interface' frontend action, using the CompilerInstance instantiated directly from the command-line in order to build the module.

Author: artemcm

include/swift/AST/DiagnosticsFrontend.def

@@ -99,8 +99,8 @@ WARNING(warning_cannot_find_locale_file,none,
       "cannot find translations for '%0' at '%1': no such file", (StringRef, StringRef))
 WARNING(warning_cannot_multithread_batch_mode,none,
       "ignoring -num-threads argument; cannot multithread batch mode", ())
-ERROR(error_cannot_ignore_interface_options_in_mode,none,
-      "'-ignore-interface-provided-options' only supported when building a module from interface ('-compile-module-from-interface')'", ())
+ERROR(error_cannot_explicit_interface_build_in_mode,none,
+      "'-explicit-interface-module-build' only supported when building a module from interface ('-compile-module-from-interface')'", ())
 ERROR(error_unsupported_option_argument,none,
       "unsupported argument '%1' to option '%0'", (StringRef, StringRef))
 ERROR(error_immediate_mode_missing_stdlib,none,

lib/FrontendTool/FrontendTool.cpp

@@ -422,17 +422,26 @@ static bool buildModuleFromInterface(CompilerInstance &Instance) {
   StringRef PrebuiltCachePath = FEOpts.PrebuiltModuleCachePath;
   ModuleInterfaceLoaderOptions LoaderOpts(FEOpts);
   StringRef ABIPath = Instance.getPrimarySpecificPathsForAtMostOnePrimary()
-    .SupplementaryOutputs.ABIDescriptorOutputPath;
-  
-  
-  
-  return ModuleInterfaceLoader::buildSwiftModuleFromSwiftInterface(
+                          .SupplementaryOutputs.ABIDescriptorOutputPath;
+
+  // If an explicit interface build was requested, bypass the creation of a new
+  // sub-instance from the interface which will build it in a separate thread,
+  // and isntead directly use the current \c Instance for compilation.
+  if (FEOpts.ExplicitInterfaceBuild)
+    return ModuleInterfaceLoader::buildExplicitSwiftModuleFromSwiftInterface(
+        Instance, Invocation.getClangModuleCachePath(),
+        FEOpts.BackupModuleInterfaceDir, PrebuiltCachePath, ABIPath, InputPath,
+        Invocation.getOutputFilename(),
+        FEOpts.SerializeModuleInterfaceDependencyHashes,
+        Invocation.getSearchPathOptions().CandidateCompiledModules);
+  else
+    return ModuleInterfaceLoader::buildSwiftModuleFromSwiftInterface(
       Instance.getSourceMgr(), Instance.getDiags(),
       Invocation.getSearchPathOptions(), Invocation.getLangOptions(),
       Invocation.getClangImporterOptions(),
       Invocation.getClangModuleCachePath(), PrebuiltCachePath,
-      FEOpts.BackupModuleInterfaceDir,
-      Invocation.getModuleName(), InputPath, Invocation.getOutputFilename(), ABIPath,
+      FEOpts.BackupModuleInterfaceDir, Invocation.getModuleName(), InputPath,
+      Invocation.getOutputFilename(), ABIPath,
       FEOpts.SerializeModuleInterfaceDependencyHashes,
       FEOpts.shouldTrackSystemDependencies(), LoaderOpts,
       RequireOSSAModules_t(Invocation.getSILOptions()));

test/ModuleInterface/IgnoreInterfaceFlags.swiftinterface renamed to test/ModuleInterface/ExplicitInterfaceBuild.swiftinterface

@@ -3,10 +3,10 @@
 
 // REQUIRES: OS=macosx
 // RUN: %empty-directory(%t)
-// Without '-ignore-interface-provided-options' this job fails because of the mismatch in 'module-name'
-// RUN: %target-swift-frontend -compile-module-from-interface -module-name IgnoresFlags -ignore-interface-provided-options -o %/t/IgnoresFlags.swiftmodule %s -verify
+// Without '-explicit-interface-module-build' this job fails because of the mismatch in 'module-name'
+// RUN: %target-swift-frontend -compile-module-from-interface -module-name IgnoresFlags -explicit-interface-module-build -o %/t/IgnoresFlags.swiftmodule %s -verify
 
 import Swift
 extension Int {
   public static var fortytwo: Int = 42
-}
+}