Frontend: Only print the -project-name flag in private and package interfaces.

Resolves rdar://130992944.

include/swift/Frontend/ModuleInterfaceSupport.h

@@ -55,6 +55,10 @@ struct ModuleInterfaceOptions {
   /// Flags which appear in all .swiftinterface files.
   InterfaceFlags PublicFlags = {};
 
+  /// Flags which appear in both the private and package .swiftinterface files,
+  /// but not the public interface.
+  InterfaceFlags PrivateFlags = {};
+
   /// Flags which appear only in the .package.swiftinterface.
   InterfaceFlags PackageFlags = {};
 

lib/Frontend/CompilerInvocation.cpp

@@ -489,13 +489,16 @@ static bool ShouldIncludeModuleInterfaceArg(const Arg *A) {
   return true;
 }
 
-static bool ShouldIncludeArgInPackageInterfaceOnly(const Arg *A,
-                                                   ArgList &Args) {
+static bool IsPackageInterfaceFlag(const Arg *A, ArgList &Args) {
   return A->getOption().matches(options::OPT_package_name) &&
          Args.hasArg(
              options::OPT_disable_print_package_name_for_non_package_interface);
 }
 
+static bool IsPrivateInterfaceFlag(const Arg *A, ArgList &Args) {
+  return A->getOption().matches(options::OPT_project_name);
+}
+
 /// Save a copy of any flags marked as ModuleInterfaceOption, if running
 /// in a mode that is going to emit a .swiftinterface file.
 static void SaveModuleInterfaceArgs(ModuleInterfaceOptions &Opts,
@@ -510,14 +513,18 @@ static void SaveModuleInterfaceArgs(ModuleInterfaceOptions &Opts,
   };
 
   RenderedInterfaceArgs PublicArgs{};
+  RenderedInterfaceArgs PrivateArgs{};
   RenderedInterfaceArgs PackageArgs{};
 
   auto interfaceArgListForArg = [&](Arg *A) -> ArgStringList & {
     bool ignorable =
         A->getOption().hasFlag(options::ModuleInterfaceOptionIgnorable);
-    if (ShouldIncludeArgInPackageInterfaceOnly(A, Args))
+    if (IsPackageInterfaceFlag(A, Args))
       return ignorable ? PackageArgs.Ignorable : PackageArgs.Standard;
 
+    if (IsPrivateInterfaceFlag(A, Args))
+      return ignorable ? PrivateArgs.Ignorable : PrivateArgs.Standard;
+
     return ignorable ? PublicArgs.Ignorable : PublicArgs.Standard;
   };
 
@@ -543,6 +550,7 @@ static void SaveModuleInterfaceArgs(ModuleInterfaceOptions &Opts,
   };
 
   updateInterfaceOpts(Opts.PublicFlags, PublicArgs);
+  updateInterfaceOpts(Opts.PrivateFlags, PrivateArgs);
   updateInterfaceOpts(Opts.PackageFlags, PackageArgs);
 }
 

lib/Frontend/ModuleInterfaceSupport.cpp

@@ -62,9 +62,12 @@ static void printToolVersionAndFlagsComment(raw_ostream &out,
       << ToolsVersion << "\n";
   out << "// " SWIFT_MODULE_FLAGS_KEY ": " << Opts.PublicFlags.Flags;
 
-  // Append flags that are for the package interface only (e.g. -package-name
-  // when -disable-print-package-name-for-non-package-interface is specified).
-  if (Opts.printPackageInterface() && !Opts.PackageFlags.Flags.empty())
+  if (Opts.InterfaceContentMode >= PrintOptions::InterfaceMode::Private &&
+      !Opts.PrivateFlags.Flags.empty())
+    out << " " << Opts.PrivateFlags.Flags;
+
+  if (Opts.InterfaceContentMode >= PrintOptions::InterfaceMode::Package &&
+      !Opts.PackageFlags.Flags.empty())
     out << " " << Opts.PackageFlags.Flags;
 
   // Insert additional -module-alias flags
@@ -101,14 +104,29 @@ static void printToolVersionAndFlagsComment(raw_ostream &out,
   }
   out << "\n";
 
-  if (!Opts.PublicFlags.IgnorableFlags.empty()) {
-    out << "// " SWIFT_MODULE_FLAGS_IGNORABLE_KEY ": "
-        << Opts.PublicFlags.IgnorableFlags << "\n";
-  }
+  // Add swift-module-flags-ignorable: if non-empty.
+  {
+    llvm::SmallVector<StringRef, 4> ignorableFlags;
 
-  // Append ignorable flags that are for the package interface only.
-  if (Opts.printPackageInterface() && !Opts.PackageFlags.IgnorableFlags.empty())
-    out << " " << Opts.PackageFlags.IgnorableFlags;
+    if (!Opts.PublicFlags.IgnorableFlags.empty())
+      ignorableFlags.push_back(Opts.PublicFlags.IgnorableFlags);
+
+    if (Opts.InterfaceContentMode >= PrintOptions::InterfaceMode::Private &&
+        !Opts.PrivateFlags.IgnorableFlags.empty())
+      ignorableFlags.push_back(Opts.PrivateFlags.IgnorableFlags);
+
+    if (Opts.InterfaceContentMode >= PrintOptions::InterfaceMode::Package &&
+        !Opts.PackageFlags.IgnorableFlags.empty())
+      ignorableFlags.push_back(Opts.PackageFlags.IgnorableFlags);
+
+    if (!ignorableFlags.empty()) {
+      out << "// " SWIFT_MODULE_FLAGS_IGNORABLE_KEY ": ";
+      llvm::interleave(
+          ignorableFlags, [&out](StringRef str) { out << str; },
+          [&out] { out << " "; });
+      out << "\n";
+    }
+  }
 }
 
 std::string

test/ModuleInterface/project-name.swift

@@ -0,0 +1,23 @@
+// RUN: %empty-directory(%t)
+
+// RUN: %target-swift-frontend -emit-module %s -I %t \
+// RUN:   -module-name Library -project-name ProjectName \
+// RUN:   -enable-library-evolution -swift-version 5 \
+// RUN:   -emit-module-interface-path %t/Library.swiftinterface \
+// RUN:   -emit-private-module-interface-path %t/Library.private.swiftinterface \
+// RUN:   -emit-package-module-interface-path %t/Library.package.swiftinterface
+
+// RUN: %target-swift-typecheck-module-from-interface(%t/Library.swiftinterface) -module-name Library
+// RUN: %target-swift-typecheck-module-from-interface(%t/Library.private.swiftinterface) -module-name Library
+// RUN: %target-swift-typecheck-module-from-interface(%t/Library.package.swiftinterface) -module-name Library
+
+// RUN: %FileCheck %s < %t/Library.swiftinterface --check-prefix CHECK-PUBLIC
+// RUN: %FileCheck %s < %t/Library.private.swiftinterface --check-prefix CHECK-NONPUBLIC
+// RUN: %FileCheck %s < %t/Library.package.swiftinterface --check-prefix CHECK-NONPUBLIC
+
+// CHECK-PUBLIC-NOT: -project-name
+
+// CHECK-NONPUBLIC: swift-module-flags-ignorable:
+// CHECK-NONPUBLIC-SAME: -project-name ProjectName
+
+public func foo() {}