Frontend: Remove the -skip-import-in-public-interface flag

include/swift/Frontend/ModuleInterfaceSupport.h

@@ -71,9 +71,6 @@ struct ModuleInterfaceOptions {
   /// Intentionally print invalid syntax into the file.
   bool DebugPrintInvalidSyntax = false;
 
-  /// A list of modules we shouldn't import in the public interfaces.
-  std::vector<std::string> ModulesToSkipInPublicInterface;
-
   /// A mode which decides whether the printed interface contains package, SPIs, or public/inlinable declarations.
   PrintOptions::InterfaceMode InterfaceContentMode = PrintOptions::InterfaceMode::Public;
   bool printPublicInterface() const {

include/swift/Option/FrontendOptions.td

@@ -1239,11 +1239,6 @@ def new_driver_path
   : Separate<["-"], "new-driver-path">, MetaVarName<"<path>">,
   HelpText<"Path of the new driver to be used">;
 
-def skip_import_in_public_interface:
-  Separate<["-"], "skip-import-in-public-interface">,
-  HelpText<"Skip the import statement corresponding to a module name "
-           "when printing the public interface.">;
-
 def disable_fine_module_tracing:
   Flag<["-"], "disable-fine-module-tracing">,
   HelpText<"Skip the emission of fine grained module tracing file.">;

lib/Frontend/CompilerInvocation.cpp

@@ -525,9 +525,6 @@ static void ParseModuleInterfaceArgs(ModuleInterfaceOptions &Opts,
       Opts.setInterfaceMode(PrintOptions::InterfaceMode::Private);
     }
   }
-  for (auto val: Args.getAllArgValues(OPT_skip_import_in_public_interface)) {
-    Opts.ModulesToSkipInPublicInterface.push_back(val);
-  }
 }
 
 /// Checks if an arg is generally allowed to be included

lib/Frontend/ModuleInterfaceSupport.cpp

@@ -339,11 +339,6 @@ static void printImports(raw_ostream &out,
       continue;
     }
 
-    if (llvm::count(Opts.ModulesToSkipInPublicInterface,
-                    importedModule->getName().str())) {
-      continue;
-    }
-
     llvm::SmallSetVector<Identifier, 4> spis;
     M->lookupImportedSPIGroups(importedModule, spis);
 

lib/FrontendTool/FrontendTool.cpp

@@ -871,7 +871,6 @@ static bool emitAnyWholeModulePostTypeCheckSupplementaryOutputs(
     // Copy the settings from the module interface to add SPI printing.
     ModuleInterfaceOptions privOpts = Invocation.getModuleInterfaceOptions();
     privOpts.setInterfaceMode(PrintOptions::InterfaceMode::Private);
-    privOpts.ModulesToSkipInPublicInterface.clear();
 
     hadAnyError |= printModuleInterfaceIfNeeded(
         Instance.getOutputBackend(),
@@ -884,7 +883,6 @@ static bool emitAnyWholeModulePostTypeCheckSupplementaryOutputs(
     // Copy the settings from the module interface to add package decl printing.
     ModuleInterfaceOptions pkgOpts = Invocation.getModuleInterfaceOptions();
     pkgOpts.setInterfaceMode(PrintOptions::InterfaceMode::Package);
-    pkgOpts.ModulesToSkipInPublicInterface.clear();
 
     hadAnyError |= printModuleInterfaceIfNeeded(
         Instance.getOutputBackend(),