[cxx-interop][symbolic interface] add a fallback for unknown generic type to be Any

Author: hyp

lib/ClangImporter/ImportType.cpp

@@ -2179,6 +2179,10 @@ findGenericTypeInGenericDecls(ClangImporter::Implementation &impl,
       llvm::find_if(genericParams, [name](GenericTypeParamDecl *generic) {
         return generic->getName().str() == name;
       });
+  // We sometimes are unable compute the exact Swift type
+  // of symbolic declarations. Fallback to using `Any` in that case.
+  if (impl.importSymbolicCXXDecls && genericParamIter == genericParams.end())
+    return impl.SwiftContext.TheAnyType;
   // TODO: once we support generics in class types, replace this with
   // "return nullptr". Once support for template classes, this will need to
   // be updated, though. I'm leaving the assert here to make it easier to

test/Interop/Cxx/symbolic-imports/print-symbolic-module-interface.swift

@@ -45,6 +45,20 @@ namespace ns {
 
 using MyType = ns::TemplateRecord<int>;
 
+template<class X>
+class OuterTemp2 {
+public:
+    template<class T, class G>
+    class InnerTemp2 {
+    public:
+        void testMe(const T& p, const X& x);
+
+        X x2;
+
+        using Y = X;
+    };
+};
+
 // CHECK:     enum ns {
 // CHECK-NEXT: struct B {
 // CHECK-NEXT:    init()
@@ -64,3 +78,11 @@ using MyType = ns::TemplateRecord<int>;
 // CHECK-NEXT:  static func freeFunction(_ x: Int32, _ y: Int32) -> Int32
 // CHECK-NEXT: }
 // CHECK-NEXT: typealias MyType = ns.TemplateRecord
+// CHECK-NEXT: struct OuterTemp2 {
+// CHECK-NEXT:   struct InnerTemp2 {
+// CHECK-NEXT:     init(x2: Any)
+// CHECK-NEXT:     mutating func testMe(_ p: Any, _ x: Any)
+// CHECK-NEXT:     var x2: Any
+// CHECK-NEXT:     typealias Y = Any
+// CHECK-NEXT:   }
+// CHECK-NEXT: }