Merge pull request #64523 from hyp/eng/libcxx-module-int

[interop][sourcekit] print submodules of CxxStdlib when printing out …

Author: hyp

test/SourceKit/InterfaceGen/gen_clang_libcxx_sdk_module.swift

@@ -0,0 +1,6 @@
+// RUN: %sourcekitd-test -req=interface-gen -module CxxStdlib -- -Xfrontend -disable-implicit-concurrency-module-import -Xfrontend -disable-implicit-string-processing-module-import -cxx-interoperability-mode=swift-5.9 -target %target-triple -sdk %sdk | %FileCheck %s
+
+// REQUIRES: OS=macosx
+
+// CHECK: import CxxStdlib.vector
+// CHECK: extension std.basic_string<Int8, char_traits<Int8>, allocator<Int8>> {

tools/SourceKit/lib/SwiftLang/SwiftEditorInterfaceGen.cpp

@@ -287,6 +287,13 @@ static bool getModuleInterfaceInfo(ASTContext &Ctx,
     ErrMsg += ModuleName;
     return true;
   }
+  if (Mod->failedToLoad() && ModuleName == "CxxStdlib") {
+    // We might fail to load the underlying Clang module
+    // for a Swift overlay module like 'CxxStdlib'. Make sure an error is reported in this case, so that we can either retry to load with C++ interoperability enabled, and if that fails, we can report this to the user.
+    ErrMsg = "Could not load underlying module for: ";
+    ErrMsg += ModuleName;
+    return true;
+  }
 
   PrintOptions Options = PrintOptions::printModuleInterface(
       Ctx.TypeCheckerOpts.PrintFullConvention);