Merge pull request swiftlang#32687 from nkcsgexi/65005528-5.3

[5.3] Front-end: disable interface file locking for the -compile-module-from-interface action

Author: nkcsgexi

lib/Frontend/ArgsToFrontendOptionsConverter.cpp

@@ -89,8 +89,6 @@ bool ArgsToFrontendOptionsConverter::convert(
   Opts.RemarkOnRebuildFromModuleInterface |=
     Args.hasArg(OPT_Rmodule_interface_rebuild);
 
-  Opts.DisableInterfaceFileLock |= Args.hasArg(OPT_disable_interface_lockfile);
-
   computePrintStatsOptions();
   computeDebugTimeOptions();
   computeTBDOptions();
@@ -143,6 +141,15 @@ bool ArgsToFrontendOptionsConverter::convert(
     Opts.RequestedAction = determineRequestedAction(Args);
   }
 
+  if (Opts.RequestedAction == FrontendOptions::ActionType::CompileModuleFromInterface) {
+    // The situations where we use this action, e.g. explicit module building and
+    // generating prebuilt module cache, don't need synchronization. We should avoid
+    // using lock files for them.
+    Opts.DisableInterfaceFileLock = true;
+  } else {
+    Opts.DisableInterfaceFileLock |= Args.hasArg(OPT_disable_interface_lockfile);
+  }
+
   if (Opts.RequestedAction == FrontendOptions::ActionType::Immediate &&
       Opts.InputsAndOutputs.hasPrimaryInputs()) {
     Diags.diagnose(SourceLoc(), diag::error_immediate_mode_primary_file);