Document setting for allowing use of explicit modules with c++ interop

Author: owenv

Sources/SWBCore/Settings/BuiltinMacros.swift

@@ -1014,7 +1014,7 @@ public final class BuiltinMacros {
     public static let SWIFT_USE_INTEGRATED_DRIVER = BuiltinMacros.declareBooleanMacro("SWIFT_USE_INTEGRATED_DRIVER")
     public static let SWIFT_EAGER_MODULE_EMISSION_IN_WMO = BuiltinMacros.declareBooleanMacro("SWIFT_EAGER_MODULE_EMISSION_IN_WMO")
     public static let SWIFT_ENABLE_EXPLICIT_MODULES = BuiltinMacros.declareEnumMacro("SWIFT_ENABLE_EXPLICIT_MODULES") as EnumMacroDeclaration<SwiftEnableExplicitModulesSetting>
-    public static let _SWIFT_EXPLICIT_MODULES_ALLOW_CXX_INTEROP = BuiltinMacros.declareBooleanMacro("_SWIFT_EXPLICIT_MODULES_ALLOW_CXX_INTEROP")
+    public static let SWIFT_EXPLICIT_MODULES_ALLOW_CXX_INTEROP = BuiltinMacros.declareBooleanMacro("SWIFT_EXPLICIT_MODULES_ALLOW_CXX_INTEROP")
     public static let _SWIFT_EXPLICIT_MODULES_ALLOW_BEFORE_SWIFT_5 = BuiltinMacros.declareBooleanMacro("_SWIFT_EXPLICIT_MODULES_ALLOW_BEFORE_SWIFT_5")
     public static let _EXPERIMENTAL_SWIFT_EXPLICIT_MODULES = BuiltinMacros.declareEnumMacro("_EXPERIMENTAL_SWIFT_EXPLICIT_MODULES") as EnumMacroDeclaration<SwiftEnableExplicitModulesSetting>
     public static let SWIFT_ENABLE_TESTABILITY = BuiltinMacros.declareBooleanMacro("SWIFT_ENABLE_TESTABILITY")
@@ -2172,7 +2172,7 @@ public final class BuiltinMacros {
         SWIFT_USE_INTEGRATED_DRIVER,
         SWIFT_EAGER_MODULE_EMISSION_IN_WMO,
         SWIFT_ENABLE_EXPLICIT_MODULES,
-        _SWIFT_EXPLICIT_MODULES_ALLOW_CXX_INTEROP,
+        SWIFT_EXPLICIT_MODULES_ALLOW_CXX_INTEROP,
         _SWIFT_EXPLICIT_MODULES_ALLOW_BEFORE_SWIFT_5,
         _EXPERIMENTAL_SWIFT_EXPLICIT_MODULES,
         SWIFT_ENABLE_BARE_SLASH_REGEX,

Sources/SWBCore/SpecImplementations/Tools/SwiftCompiler.swift

@@ -1377,7 +1377,7 @@ public final class SwiftCompilerSpec : CompilerSpec, SpecIdentifierType, SwiftDi
 
         // rdar://122829880 (Turn off Swift explicit modules when c++ interop is enabled)
         guard scope.evaluate(BuiltinMacros.SWIFT_OBJC_INTEROP_MODE) != "objcxx" && !scope.evaluate(BuiltinMacros.OTHER_SWIFT_FLAGS).contains("-cxx-interoperability-mode=default") else {
-            return scope.evaluate(BuiltinMacros._SWIFT_EXPLICIT_MODULES_ALLOW_CXX_INTEROP)
+            return scope.evaluate(BuiltinMacros.SWIFT_EXPLICIT_MODULES_ALLOW_CXX_INTEROP)
         }
 
         // Disable explicit modules in the pre-Swift-5 language modes to avoid versioned API notes confusion.

Sources/SWBUniversalPlatform/Specs/Swift.xcspec

@@ -1021,6 +1021,13 @@
                 Category = "General";
                 Description = "Coordinates the build of the main module's modular dependencies via explicit tasks scheduled by the build system.";
             },
+            {
+                Name = "SWIFT_EXPLICIT_MODULES_ALLOW_CXX_INTEROP";
+                Type = Boolean;
+                DisplayName = "Use Explicitly Built Modules with C++ Interoperability";
+                Category = "General";
+                Description = "Enable use of explicitly built modules in Swift code which has adopted C++ interoperability.";
+            },
             {
                 Name = "SWIFT_ENABLE_COMPILE_CACHE";
                 Type = Boolean;