ModuleInterface: Avoid printing @_spi enum case decls in public swiftinterfaces.

rdar://72873771

Author: tshortli

lib/AST/ASTPrinter.cpp

@@ -276,6 +276,21 @@ PrintOptions PrintOptions::printSwiftInterfaceFile(ModuleDecl *ModuleToPrint,
           return false;
       }
 
+      // Skip enum cases containing enum elements we wouldn't print.
+      if (auto *ECD = dyn_cast<EnumCaseDecl>(D)) {
+        auto elements = ECD->getElements();
+        if (!elements.empty()) {
+          // Enum elements are usually not printed, so we have to override the
+          // print option controlling that. We only check the first element
+          // because all the elements in a single case decl should have the same
+          // characteristics.
+          PrintOptions optionsCopy = options;
+          optionsCopy.ExplodeEnumCaseDecls = true;
+          if (!shouldPrint(elements[0], optionsCopy))
+            return false;
+        }
+      }
+
       return ShouldPrintChecker::shouldPrint(D, options);
     }
   };

test/SPI/private_swiftinterface.swift

@@ -34,14 +34,6 @@
 // RUN: %target-swift-frontend -typecheck-module-from-interface -I %t %t/Main.swiftinterface
 // RUN: %target-swift-frontend -typecheck-module-from-interface -I %t %t/Main.private.swiftinterface -module-name Main
 
-/// Serialize and deserialize this module, then print.
-// RUN: %target-swift-frontend -emit-module %s -emit-module-path %t/Merged-partial.swiftmodule -swift-version 5 -I %t -module-name Merged -enable-library-evolution
-// RUN: %target-swift-frontend -merge-modules %t/Merged-partial.swiftmodule -module-name Merged -emit-module -emit-module-path %t/Merged.swiftmodule -I %t -emit-module-interface-path %t/Merged.swiftinterface -emit-private-module-interface-path %t/Merged.private.swiftinterface -enable-library-evolution -swift-version 5 -I %t
-// RUN: %FileCheck -check-prefix=CHECK-PUBLIC %s < %t/Merged.swiftinterface
-// RUN: %FileCheck -check-prefix=CHECK-PRIVATE %s < %t/Merged.private.swiftinterface
-// RUN: %target-swift-frontend -typecheck-module-from-interface -I %t %t/Merged.swiftinterface
-// RUN: %target-swift-frontend -typecheck-module-from-interface -I %t %t/Merged.private.swiftinterface -module-name Merged
-
 /// Both the public and private textual interfaces should have
 /// SPI information with `-library-level spi`.
 // RUN: %target-swift-frontend -typecheck %s -emit-module-interface-path %t/SPIModule.swiftinterface -emit-private-module-interface-path %t/SPIModule.private.swiftinterface -enable-library-evolution -swift-version 5 -I %t -module-name SPIModule -library-level spi
@@ -157,6 +149,34 @@ public struct PublicStruct {
   // CHECK-PUBLIC-NOT: spiWrappedDefault
 }
 
+@_spi(S) public enum SPIEnum {
+// CHECK-PRIVATE: @_spi(S) public enum SPIEnum
+// CHECK-PUBLIC-NOT: SPIEnum
+
+  case spiEnumCase
+  // CHECK-PRIVATE: case spiEnumCase
+  // CHECK-PUBLIC-NOT: spiEnumCase
+}
+
+public enum PublicEnum {
+  case publicCase
+  // CHECK-PUBLIC: case publicCase
+  // CHECK-PRIVATE: case publicCase
+
+  @_spi(S) case spiCase
+  // CHECK-PRIVATE: @_spi(S) case spiCase
+  // CHECK-PUBLIC-NOT: spiCase
+
+  @_spi(S) case spiCaseA, spiCaseB
+  // CHECK-PRIVATE: @_spi(S) case spiCaseA, spiCaseB
+  // CHECK-PUBLIC-NOT: spiCaseA
+  // CHECK-PUBLIC-NOT: spiCaseB
+
+  @_spi(S) case spiCaseWithPayload(_ c: SomeClass)
+  // CHECK-PRIVATE: @_spi(S) case spiCaseWithPayload(_: {{.*}}.SomeClass)
+  // CHECK-PUBLIC-NOT: spiCaseWithPayload
+}
+
 @_spi(LocalSPI) public protocol SPIProto3 {
 // CHECK-PRIVATE: @_spi(LocalSPI) public protocol SPIProto3
 // CHECK-PUBLIC-NOT: SPIProto3