Merge pull request #75644 from swiftlang/gaborh/embedded-swift

[cxx-interop] Fix crash with reverse interop in Embedded Swift

Author: Xazax-hun

lib/PrintAsClang/PrintSwiftToClangCoreScaffold.cpp

@@ -186,10 +186,22 @@ void printPrimitiveGenericTypeTraits(raw_ostream &os, ASTContext &astContext,
   if (!(isSwiftIntLong && !isInt64Long))
     primTypesArray = primTypesArray.drop_back(2);
 
+  // We do not have metadata for primitive types in Embedded Swift.
+  bool embedded = astContext.LangOpts.hasFeature(Feature::Embedded);
+
   for (Type type : primTypesArray) {
     auto typeInfo = *typeMapping.getKnownCxxTypeInfo(
         type->getNominalOrBoundGenericNominal());
 
+    if (!isCForwardDefinition) {
+      os << "template<>\n";
+      os << "static inline const constexpr bool isUsableInGenericContext<"
+         << typeInfo.name << "> = true;\n\n";
+    }
+
+    if (embedded)
+      continue;
+
     auto typeMetadataFunc = irgen::LinkEntity::forTypeMetadata(
         type->getCanonicalType(), irgen::TypeMetadataAddress::AddressPoint);
     std::string typeMetadataVarName = typeMetadataFunc.mangleAsString();
@@ -201,10 +213,6 @@ void printPrimitiveGenericTypeTraits(raw_ostream &os, ASTContext &astContext,
       continue;
     }
 
-    os << "template<>\n";
-    os << "static inline const constexpr bool isUsableInGenericContext<"
-       << typeInfo.name << "> = true;\n\n";
-
     os << "template<>\nstruct TypeMetadataTrait<" << typeInfo.name << "> {\n"
        << "  static ";
     ClangSyntaxPrinter(os).printInlineForThunk();

test/Interop/SwiftToCxx/core/embedded-swift.swift

@@ -0,0 +1,11 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend %s -typecheck -module-name Core -target arm64-apple-macos15.0 -enable-experimental-feature Embedded -clang-header-expose-decls=all-public -emit-clang-header-path %t/core.h
+// RUN: %FileCheck %s < %t/core.h
+
+// REQUIRES: OS=macosx
+
+public func id(_ x: Int) -> Int {
+    return x
+}
+
+// CHECK-NOT: TypeMetadataTrait<bool>